WO2013105110A2 - An improved fire extinguisher - Google Patents

Abstract

An improved fire extinguisher (100) for extinguishing all kinds of fire at early stage preventing them to expand and cause high damages. The proposed fire extinguisher (100) extinguishes fire without affecting the properties or damaging the material involved in the fire. The proposed fire extinguisher (100) alleviates all the problems related to the existing fire extinguisher assemblies such as corrosion, leakage, bursting and splashing.

Description

Description

AN IMPROVED FIRE EXTINGUISHER

FIELD OF INVENTION

The proposed invention relates to an improved fire extinguisher. More particularly, it relates to an improved fire extinguisher which can be used to extinguish all kinds of fire without affecting the properties or damaging the material involved in the fire as well as to alleviate the problems related to the existing fire extinguisher assemblies.

BACKGROUND OF INVENTION j

Fire incidents can happen in many ways depending on the cause of fire outbreak, but broadly there are two types of fires, one is natural and other is manmade. Forest fires can be either due to natural or manmade reasons. All residential and non-residential structural fires are largely incidentally or by errors or due to lack of awareness. Similarly, all industrial and chemical fires are due to explosions or fires made by human errors or due to machine failures. Whether natural or erroneous, fire takes place in presence of fire catching material and flammable substances like fuel, flammable gases and alike. The fire continues to spread until the heat transfer and oxygen supply is ceased.

Fires which are considered as natural are basically earthquake, volcanic eruption and lightning - generated fires. The fire and explosion risk associated with an earthquake is very complex. Compared with ordinary fires, the fire and explosion hazard related to earthquakes can constitute substantial and heavy risk. Damage to natural gas systems during an earthquake is a major cause of large fires.

Fire caused by human/machine errors are considered as manmade fires, e.g. industrial or chemical fire, disasters, fires at social gatherings due to Electrical short circuit fires, accidental fire and kitchen-fires. Rural and urban residential and non-residential structural fires are also largely manmade fires. Any confined fire could be due to many reasons like, cooking fire confined to container, chimney or fuel fire confined to chimney, incinerator overload or malfunction, fuel burner/boiler malfunction, and trash fire.

Causes may include:

• Cooking/ heating equipment

• Electrical

• Open flame or ember

• Appliance, tool or air conditioning · Human errors

• Other heat source

• Intentional

A fire extinguisher or extinguisher, flame extinguisher is an active fire protection device used to extinguish or control small fires, often in emergency situations by discharging out the extinguishant from the extinguisher where an extinguishant is an agent which extinguishes the fire. Typically, a fire extinguisher consists of a hand-held cylindrical pressure vessel containing an agent which can be discharged to extinguish a fire. For a fire extinguisher to be proficient the strength and construction of the extinguisher assembly as well as the composition of the extinguishant are equally essential factors.

PRIOR ART

Conventionally, various types of fire extinguishers are available, each used to extinguish different types of fire. Depending upon the type of the fire it can extinguish, each of the extinguishers has different extinguisher assembly and respective extinguishant filled in it. They are characterized as below: 1) Water type Extinguisher:

This type of extinguishers can only be used to extinguish fire mainly of solid material like wood, paper and cloth etc. Water acts as a coolant eliminating heat which breaks the chain reaction of fire that is air, heat and fuel. Since heat is eliminated using water fire cannot be continued.

But the water extinguisher cannot be used to extinguish fire associated with

Flammable gases

Flammable liquids

Electrical Equipment

■S Cooking oils and fats.

It is because water is heavy in terms of weight and flammable liquids are light in weight, water goes down and flammable liquids start floating above water so fire cannot be extinguished. The same applies to flammable gases, cooking oils and fats. As water is having tendency of conducting electricity, it increases the risks of fatal accidents such as getting electrical shock to the operators of such extinguishers and hence cannot be used to extinguish fire associated with electrical equipments.

Even though water helps to extinguish solid fire like wood, paper and cloth, it is having residual effect and hence requires cleaning once fire extinguishes. Further, even if it extinguishes fire, the remaining material involved in the fire gets damaged.

2) Foam type Extinguisher:

Foam being light in weight it has a tendency to remain on the upper surface including solid materials and flammable liquid so it can be used for solid, liquid and cooking oil fire. However, due to water content high risk of altering the properties of solids, flammable liquids, cooking oil and fats are associated with such type extinguishers. Also, the foam extinguisher cannot be used for electrical equipment because the foam contains water. Since water is conductor of electricity, it is dangerous to the operators of such extinguisher. Further, it cannot be used on flammable gases because flammable gases are lighter in weight compared to foam, so the flammable gases escape out and hence fire cannot be extinguished properly.

3) Dry Chemical Powder (DCP):

This type of extinguisher can be used to extinguish fire associated with solid, flammable gases, flammable liquid and electrical equipment. DCP molecules (particles) have tendency to expand when they get exposed to temperature. All DCP molecules together make a cloud on the burning object and cut off the Oxygen supply. Since DCP is solid substance, they also rest on solid substance which are burning and control fire by physically covering the burning object. At the same time since these particles are having tendency to expand they become light in weight and hence also capable to control flammable gases and flammable liquid fire. Further, DCP is having no electrical conductivity if they do not contain moisture, hence they can also be used to extinguish electrical fire. But DCP being solid substance in form of powder, get mixed or dissolved with the cooking oil and fats and contaminates it when used to extinguish fire associated to it, hence they cannot be used to extinguish the cooking oil and fats fire. In addition, dry powder being solid substance it requires cleaning after the use of such extinguishers. Further, being a solid powder many times it is difficult to propel out through deep tube, spring, plunger, valve and discharge nozzle assembled at 90°. The deep tube is in vertical position and discharge nozzle is at 90°. It is difficult for DCP being a solid substance to travel at 90°. Further, in this type of fire extinguisher the nozzle diameter is much less than the deep tube diameter. DCP is also s bject to contamination as it losses the property due to the limited shelf life in a due course of time. In addition, discharging dry chemical powder invites visibility problem and injury to the person on whom it is discharged directly by mistake.

4) Carbon dioxide (C02):

Carbon dioxide fire extinguisher can be used for extinguishing fires on flammable liquids, electrical equipments and cooking Oils and fats. Being light in weight, carbon dioxide is capable to float temporarily on flammable liquid fire and on cooking oil and fats cutting the oxygen supply to extinguish the fire. Further, C02 ' is non-conductor of electricity and hence it can be used to extinguish electrical fire also.

However, Carbon dioxide being in a gaseous form requires high pressure of around 35 kg/ cm² to get converted into liquid to store it into cylinder. Therefore, the cylinder valve thickness is very high to withstand the pressure for even 5kg capacity of CO2 gas. The total weight of extinguisher would be around 18 kg which is difficult to lift for everyone and to run the spot of fire. Further, CO2 on discharge gets mixed into the atmosphere hence it is not effective for solid fires. It is neither able to cool nor able to provide blanket of C0₂ failing to help to control solid fire. The same applies with flammable gasses. Further, C0₂ being a gas is not effectively able to cover the flammable gases to cut off the oxygen supply and hence fail to extinguish such fires. Another practical problem of CO2 is that though it itself is not a conductor of electricity, but when it get discharged from high pressure to low pressure it generates cooling effect and condenses the atmospheric moisture on the discharge pipe which conducts the electricity. This results in high risks of cold burns to the operator. In addition, an annoying and fearing sound is generated by this type of extinguisher that may scare the operator to use the same. Additionally, the valve assembly does not withstand the pressure with which CO2 is stored in the extinguisher and may lead to leakage. This may further lead to failure of the extinguisher to serve the purpose when actually required.

CONVENTIONAL FIRE EXTINGUISHERS

EXTINGUISHER TYPE OF FIRE

SR. TYPE SOLID FLAMMABLE FLAMMABLE ELECTRICAL COOKING NO. FIRE LIQUIDS GASES EQUIPMENTS OILS AND

FATS

1 Water Yes No No No No

2 Foam Yes Yes No No Yes

3 Dry Yes Yes Yes Yes No

Powder

4 C02 No Yes No Yes Yes

The extinguishers in the prior art as described above, are summarized in the table above.

Above mentioned different types of extinguishers are required to extinguish different types of fire. With these conventional fire extinguishers, there was always the confusion to the operator of extinguisher to select the appropriate type of extinguisher suitable to the type of material involved in the fire. Therefore, there is an unmet need to develop a fire extinguisher that extinguishes all types of fire and alleviates the problems associated with the conventional fire extinguishers.

Common problems associated with all the above described fire extinguishers is that, they are usually made of Mild steel (M.S) or other metals which imparts a high risk of corrosion leading to leakage and secondly because of the inappropriate valve design in which the extinguishant has to travel through deep tube, spring, plunger, valve body and nozzles at 90°, whereby the extinguishant gets stuck on the spring and plunger rubber ring resulting in leakage in most of the cases. Other problems relate to the inefficiency of the valve assembly to withstand the pressure of the extinguishing agent filled in the extinguisher etc.

The above described conventional types of extinguishers are broadly characterized into two categories based on its construction. The details of the same are as below:

1. Stored pressure and

2. Cartridge-operated. In stored pressure units, the expellant is stored in the same chamber as the extinguishing agent itself. Depending on the agent used, different propellants are used. With dry chemical extinguishers, nitrogen is typically used; while water and foam extinguishers typically use air.

Cartridge-operated extinguishers contain the expellant gas in a separate cartridge that is punctured prior to discharge, exposing the propellant to the extinguishing agent. They have the advantage of simple and prompt recharge, allowing an operator to discharge the extinguisher, recharge it, and return to the fire in a reasonable amount of time. Unlike stored pressure types, these extinguishers use compressed carbon dioxide instead of nitrogen. Cartridge operated extinguishers are available in dry chemical and dry powder types and in water, wetting agent, foam, dry chemical powder. As mentioned earlier, the conventional extinguishers are generally made up of Mild Steel and therefore they, are subject to face corrosion problem resulting into the reduced metal thickness of extinguisher shell, cylinder or a container in a due course of time. Hence, they fail to withstand the cartridge pressure used to push the extinguishant out of the container to extinguish the fire. Ultimately the purpose of extinguishing the fire is not achieved. These extinguishers require frequent hydrostatic pressure testing to ensure the availability of required strength of the extinguisher wall, cylinder or container.

Further, the conventional type extinguishers have two levers, one for holding the extinguisher and other to press and discharge the content of the extinguisher. The said levers are generally made of Mild Steel metal sheet due to which they get corroded completely and ^' either losses strength or are found broken.

Further, the safety lock pin is used to prevent tempering and malfunctioning of the valve for the safety reason where the conventional fire extinguishers use plastic, mild steel or galvanized metals for the said safety lock pins which get jammed because of corrosion and become impossible to disengage at the time of use, failing to serve the purpose of extinguishing the fire.

Further, the conventional type extinguishers have external installation bracket which are usually made out of Metal and M.S. fitting like screws or nails. Such external installation brackets are most of the times found under heavy corrosion. Once corroded, they are no more in a position to withstand the extinguisher weight and hence the extinguisher has high risks of falling down leading to leakage or if the bracket gets broken, it is not placed on the required place or missing from the proper place of installation. Further, in conventional extinguishers, cartridge is used to generate the required pressure in the extinguisher to push out the extinguishant. The conventional technology using cartridge has reported fatal accidents because, of explosion of the main cylinder of the extinguisher.

Further, the conventional extinguisher having cartridge design needs to be punchered to generate required pressure. The operator has to strike his hand on the valve plunger. Many times it happens that since the plunger pin gets jammed in spite of repeated attempt of punchering the disc of cartridge, the operator fails to do so and hence lead to hand injury. Once the fire extinguisher cartridge gets punchered, there is immediate discharge of high pressure in outer container. Because of corrosion the outer container fails to withstand cartridge high pressure and hence extinguisher explodes and invites injury or fatal accident to the operator and at the same time all the extinguishant is getting flashing out.

Another major disadvantage of conventional type extinguishers is leakage due to which, there is no pressure available in the extinguisher at time of fire. This is because of the valve design used in conventional types of fire extinguishers. Almost every conventional extinguisher is having compact valve assembly having a spring loaded plunger made out of either plastic, Mild Steel or Brass metal. The plunger seat is having rubber Ό' ring. Once operated, the plunger does not necessarily come back on its original place. The rubber. Ό' ring gets some impression because of constant pressure and does not come back on the same place subjecting to the leakage. The rubber component is having very short shelf life and has some porosity, thus having limited capacity to hold the pressure for long time. Hence, they do not ensure full proof leakage free operation. Further, the valve design is such that the extinguishant either it is water, foam or dry chemical powder passes through the spring due to which they get struck with the spring and create obstacle to perform spring operation and also helps to accelerate the corrosion process because of water or foam type extinguishant. Another reason for the leakage is that the coil spring which is normally under pressure gets jammed because of having constant pressure and develops metal fatigue or it loses its strength over a period of time because of corrosion. This design is not reliable in terms of maintaining pressure; it is subject to leak over a period of time. -

Further, the conventional type extinguishers have plastic deep tube having chamfered cut at the bottom at around 45° which leaves behind unused extinguisharit up to 10% of the total quantity after complete discharge which is having direct effect on the efficiency of extinguishing the fire. Moreover, because of plastic material there are chances of siphon tube getting bend, crack or can even break resulting into the pressure leakage and failure of the extinguisher. The conventional fire extinguishers have bottom ring of plastic or M.S. or other metal. In such extinguishers the welding of bottom ring gets open and the extinguisher gets leaked on falling.

Yet another major disadvantage of conventional type extinguishers is that the extinguishant is filled in the cylinder at high pressure which may lead to bursting and splashing off of the extinguisher from the user's hand leading to injury.

Further, the conventional type extinguishers have single hole plastic nozzle within built cap which results in a jet type discharge of the extinguishing agent resulting in splashing of fire. Because of the single hole nozzle and the cap design, the quantity and the spray pattern of the extinguishant is not capable to cover the fire instantaneously thus it fails to- control the fire. Further, with a single hole the quantity which is coming out is getting burned into the fire or decomposes and losses the extinguishing capacity resulting into failure of extinguishing the fire. Thus, such conventional type extinguishers are not reliable as due to the single hole plastic nozzle they take longer time to extinguish the fire and fail to prevent the spreading of fire.

Further, the conventional type extinguishers have plastic or rubber discharge pipe. Such conventional type discharge pipe has limited efficiency and life to withstand climatic conditions such as sunlight, rain water, cold and hot air, air pollution like petroleum, solvent or chemical fumes. Hence, such conventional type discharge pipes are often found cracked and broken. In addition, plastic and rubber have poor mechanical strength.

Further, the conventional type extinguishers use readymade pressure gauge available in the market. Many times they are not calibrated in reference to the type of extinguishant used in the extinguisher, thus technically they do not indicate the right designed pressure. Hence, they are responsible for the pressure related problems associated with the working of the extinguisher such as splashing of the material on fire, leakage, metal fatigue and other problems related to valve operation.

Further the conventional type extinguishers is having discharge nozzle assembled at 90° in the main valve body. The extinguishant while traveling vertically from container to deep tube to spring to plunger further to main valve body and immediately it needs to travel 90° from the nozzle, reducing the speed and pressure ultimately losing the extinguishing efficiency by getting jammed. DISADVANTAGES OF PRIOR ART

Different types of fire extinguishers are available in the market and are used to extinguish different types of fire, but each of the conventional extinguishers suffers from at least one of the following problems:

• There is always confusion to the operator to select the appropriate type of extinguisher suitable to the type of material involved in the fire.

Most of the conventional fire extinguishers are made up of Mild Steel or other such metals which have a high risk of corrosion and related problems.

In most of the fire extinguishers available, the safety lock pin is made of plastic or Mild Steel which breaks off easily due to corrosion or is difficult to disengage leading to failure of extinguisher to serve the purpose when required.

Most of them have installation brackets made of Mild Steel which fails to withstand the weight of the fire extinguisher once it gets corroded.

Most of them suffer from problems of leakage due to corrosion of the cylinder and the valve assembly. .

Most of them fail to serve the purpose when required as the extinguishant get leaked and the extinguishers are found empty when are actually required.

Most of the extinguishing agents used in the^' conventional fire extinguishers require high pressure to be converted to compressed liquid form by pressurizing to store. Most of them involve extinguishant filled with high pressure that further leads to problems of leakage, splashing off and bursting.

In most of the conventional fire extinguishers, the cylinder in which extinguishant is filled with high pressure requires the extinguisher to be thick walled so as to withstand the high pressure with which the extinguishant is filled.

Most of them are heavy in weight nearly 16 to 17 kilograms and so difficult to lift by everyone especially when there is a panic situation at the site of fire.

Most of them have residual effect and hence requires cleaning after extinguishing the fire.

The existing fire extinguishers with residual effect cannot be used to extinguish fires associated with cooking oils and fats as this leads to change in the properties of the material involved in fire and renders this material useless.

Many of the conventionally used extinguishers use extinguishant that is a conductor of electricity resulting in high risks of fatal accidents like electric shocks and hence cannot be used to extinguish electrical fires.

Many of the extinguishers involve the extinguishant which is higher in weight compared to the material involved in fire such as flammable gases and hence fail to extinguish such fire as the extinguishant settles down.

Many of them involve the extinguishant which get mixed, dissolved or contaminate the material involved in fire; for example, DCP extinguishers when used to extinguish fire associated with oils and fats, it contaminates the material rendering it of no further use.

Many of them contain extinguishant that are difficult to expel out properly.

Many of them contain extinguishant that has a limited shelf life.

Many of them impart problems of discharge visibility.

Many of them contain extinguishant is light in weight and mixes with the atmosphere when discharged failing to extinguish the fire.

Most of them use extinguishant that fail to cut off the oxygen supply to the fire and hence fail to extinguish the fire.

Many of. them lead to cold burns to the operator of the extinguisher.

Most of them are one time use type of extinguishers and all the extinguishant is expelled out as the discharge of the extinguishant cannot be stopped until the extinguisher gets completely empty.

Many of them having cartridge design needs to be punchered to generate required pressure which requires skill or else there are chances of splashing off or bursting.

Many of them with cartridge design fails to operate as the plunger pin gets jammed and increases the risk of injury to the operator.

Most of them have compact valve assembly having a spring loaded plunger made out of either plastic, Mild Steel or Brass metal where the extinguishant gets stuck becoming obstacle for spring operation and corrosion related problems. Most of them have a plunger seat having rubber Ό' ring which is porous and has with a short shelf life leading to leakage.

Most of them have coil spring constantly under high pressure that leads the coil to get jammed due to metal fatigue and loose its strength due to corrosion leading to leakage.

Most of them have a plastic deep tube with less durability leading to bends, cracks or breakage because of high pressure and thereby failure of the extinguisher.

Most of them have plastic deep tube having chamfered cut at the bottom at around 45" that leaves behind unused extinguishant up to 10% of the total quantity after complete discharge which affects the efficiency of extinguishing the fire.

In most of them, the bottom ring is made up of Mild Steel or plastic or other such metal where the welding of bottom ring gets open and the extinguisher gets leaked on falling.

Most of them have single hole plastic nozzle within built cap which results in a jet type discharge of the extinguishing agent resulting in splashing of fire and hence fails to control the spreading of fire.

Most of them have plastic or rubber discharge pipe which has poor mechanical strength, limited efficiency and shelf life to withstand climatic conditions such as sunlight, rain water, cold and hot air, air pollution like petroleum, solvent or chemical fumes and hence gets easily cracked or broken failing to serve the purpose when required.

Most of them use readymade pressure gauge available in the market which are not calibrated in reference to the type of extinguishant used in the extinguisher, thus they do not indicate the right designed pressure and are responsible for the problems associated with the working of the extinguisher such as splashing of the material on fire, leakage, metal fatigue and other problems related to valve operation. They result in generation of toxic gases in higher amount due to the chemical reaction and incomplete combustion.

Different types of fire extinguishers have been used since many years to control different types of fire. However, there is an unmet need to develop a fire extinguisher that extinguishes all types of fire and alleviates the problems associated with the conventional fire extinguishers.

OBJECTS OF THE PRESENT INVENTION

The main object of the present invention is to provide an improved fire extinguisher which can be used to extinguish all kinds of fire without affecting the properties or damaging the material involved in the fire as well as to alleviate the problem related to the existing fire extinguisher assemblies.

Another object of the present invention is to provide an improved fire extinguisher which controls the fire effectively at early stage preventing it to spread further and causes massive damages.

Another object of the present invention is to provide an improved fire extinguisher for the use of which, there is no confusion to the operator to select the appropriate type of extinguisher suitable to the type of material involved in the fire. Another object of the present invention is to provide an improved fire extinguisher which effectively extinguishes the base of fire instantaneously.

Another object of the present invention is to provide an improved fire extinguisher having extinguishant which is filled in the cylinder at significantly reduced pressure.

Yet another object of the present invention is to provide an improved fire extinguisher having extinguishant which does not alter the properties of the objects and material on fire due to its non reactive nature, enabling the further use of objects and material on fire.

Yet another object of the present invention is to provide an improved fire extinguisher having extinguishant which does not contaminate with the objects and material on fire.

Yet another object of the present invention is to provide an improved fire extinguisher having extinguishant which does not damage the objects and material on fire.

Yet another object of the present invention is to provide an improved fire extinguisher having extinguishant which does not have residual effects and hence cleaning is not required after extinguishing the fire.

Yet another object of the present invention is to provide an improved fire extinguisher which can be used to extinguish electrical fire also.

Yet another object of the present invention is to provide an improved fire extinguisher which effectively extinguishes the fire associated with flammable gases. Yet another object of the present invention is to provide an improved fire extinguisher which extinguishes the fire associated with cooking oils & fats and alike without contaminating the material involved in the fire.

Yet another object of the present invention is to provide an improved fire extinguisher which contains extinguishant that has a long shelf life and hence is durable.

Yet another object of the present invention is to provide an improved fire extinguisher which does not create discharge visibility problems.

Yet another object of the present invention is to provide an improved fire extinguisher which does not impart any risk of cold burns to the operator.

Yet another object of the present invention is to provide an improved fire extinguisher which can be used for more than one time as it is possible to stop the expelling out of the extinguishant from the extinguisher as soon as fire is extinguished and use the rest of the extinguishant when another time the fire takes place.

Yet another object of the present invention is to provide an improved fire extinguisher that does not require any skill to operate and is very convenient to use by everyone.

Yet another object of the present invention is to provide an improved fire extinguisher which has no risk of splashing off of the extinguisher from the operator's hand.

Yet another object of the present invention is to provide an improved fire extinguisher wherein there is no risk of injury to the operator. Yet another object of the present invention is to provide an improved fire extinguisher which has no risks of bursting.

Yet another object of the present invention is to provide an improved fire extinguisher wherein generation of toxic gases is considerably reduced.

Yet another object of the present invention is to provide an improved fire extinguisher wherein problems of corrosion are eliminated.

Yet another object of the present invention is to provide an improved fire extinguisher which is completely leak proof.

Yet another object of the present invention is to provide an improved fire extinguisher wherein the safety lock pin is easy to disengage when required.

Yet another object of the present invention is to provide an improved fire extinguisher wherein the installation brackets are stronger and withstands the weight of the fire extinguisher.

Yet another object of the present invention is to provide an improved fire extinguisher which is almost four times lighter in weight compared to the conventional fire extinguishers.

Yet another object of the present invention is to provide an improved fire extinguisher wherein the extinguishant expels out properly.

Yet another object of the present invention. is to provide an improved fire extinguisher wherein the deep tube is highly durable and has no risks of bends, cracks or breakage because of pressure. Yet another object of the present invention is to provide an improved fire extinguisher which has enhanced the efficiency of extinguishing the fire. Yet another object of the present invention is to provide an improved fire extinguisher prevents leakage even after falling.

Yet another object of the present invention is to provide an improved fire extinguisher which efficiently controls the spreading of fire.

Yet another object of the present invention is to provide an improved fire extinguisher discharge pipe has a higher mechanical strength, efficiency and shelf life to withstand climatic conditions such as sunlight, rain water, cold and hot air, air pollution like petroleum, solvent or chemical fumes and hence does not get cracked or broken easily.

Yet another object of the present invention is to provide an improved fire extinguisher wherein problems related to valve operation are eliminated.

BRIEF DESCRIPTION OF DRAWINGS

Fig.1 : Shows fragmented view, of proposed fire extinguisher

Fig.2A : Shows side view of proposed fire extinguisher in resting position

Fig.2B Shows side view of proposed fire extinguisher in working position

Fig.3A : Front view of the plastic nozzle

Fig.3B : Rear view of the plastic nozzle Fig.3C Side view of the plastic nozzle

Fig.3D Perspective view of the plastic nozzle

DESCRIPTION OF INVENTION

The features, nature and advantages of the disclosed subject matter will become more apparent from the detail description set forth below when taken in conjunction with the drawings in which like reference numerals identify correspondingly throughout.

Meaning of reference numerals used in figures 1 to 3:

100 : Fire extinguisher

101 : Cylinder assembly

102 : Valve assembly

1 : Cylinder

2 : Valve body

2A : Lower connecting means

2B : Upper connecting means

2C : Side connecting means 1

2D : Side connecting means 2

3AL : Lower ball washer

3AU Upper ball washer

3B : Side pin washer

3C : Washer

3D : Top nut washer

4 : Rotating S.S. ball

5 : Side pin free nut

6A : Ball pin 6B : Nut

7 : Top nut

8 : Cap nut

9A : Coil spring (at side connecting , means 1 )

9B : Coil spring (at side connecting means 2)

10 : Valve lever

1 1 : Valve lever side bolt

12 : Discharge pipe

13 : . Plastic nozzle

14 : Nozzle deflector

15 : Deflector screw .

16 : Nozzle cap

17 : Handle

18 : Pressure gauge

19 : Deep tube

20 : Safety lock pin

21 : Chain link

22 : Chain ring

23 : Male installation bracket

24 : Tamper seal

25 : Extension with hole

The embodiment of the proposed invention is to provide an extinguishant used to extinguish the fire effectively and instantaneously. The composition of extinguishant in the proposed fire extinguisher ( 100) mainly comprises of extinguishing agent and expellant, whereby the extinguishing agent is a mixture of 2,2- Dichloro- l , l , l -trifluoroethane and Tetrailuoromethane and whereas the expellant is^' argon gas of 99.9% purity. The composition of extinguishant of the proposed fire extinguisher (100) comprises of: 2,2-Dichloro- l , l , l-trifluoroethane in proportion range of 90 to 95%,

> Tetrailuoromethane in proportion range of 3 to 6% and

> Argon gas in proportion range of 1.5 to 3.5%.

The preferable proportion of the said 2,2-Dichloro- 1 , 1 , 1- trifluoroethane is 93.1%.

The preferable proportion of the said Tetrailuoromethane is 4.3%.

The preferable proportion of the said argon gas is 2.6%.

Various physical and chemical properties of the extinguishant of the proposed invention are as below:

Physical Properties:

Property Typical Values

Color Colorless

Physical state Liquid at room temperature

Boiling Point 25.5°C ( 81.7 F ) at 760 mmHg

Vapor Pressure 1 1.2 psig at 25 C ( 77 F )

Vapor Density 6.07kg/m3

Molecular weight Approx 140Da

Odor Ether (slight)

Ozone Depletion 0.0098

Chemical Properties:

> The said extinguishant of the proposed fire extinguisher ( 100) being volatile in nature has the lower boiling point of 25.6°C is in liquid form at room temperature. Thus, the said extinguishant is filled up and stored in the cylinder ( 1) at lower pressure of 100PSI, preventing all the problems related to the high pressure.

> The extinguishant of the proposed fire extinguisher ( 100) when stored inside the cylinder ( 1) is in liquid state. The said extinguishant when discharge out from the fire extinguisher ( 100) is in liquid form and rapidly gets converted into gaseous form. The said extinguishant gets discharged in conical pattern and creates a uniform shower of extinguishant covering the fire, base instantaneously with large diameter and extinguish the fire by cooling and cutting off the oxygen supply.

> As the said extinguishant of the proposed fire extinguisher ( 100), discharges out the extinguishant at constant pressure of 100PSI in liquid form and then gets converted into gaseous form is able to extinguish the fire on solid objects and materials.

> The extinguishant of the proposed fire extinguisher ( 100) when comes in contact with flame boundary or flame surface of the flammable gases reacts and extinguishes the fire completely by cutting off the oxygen supply and by entirely covering the base of fire by facilitating the flow of extinguishant in shower form.

> As the density of the extinguishant of the proposed fire extinguisher (100) is 6.07kg/m3 which is less than vapour density of water and more than the vapour density of air, the proposed extinguishant neither settles down nor readily mixes with the atmosphere unlike the extinguishants of the solid extinguisher and CO₂ extinguisher, respectively.

> The extinguishant of the proposed fire extinguisher ( 100) is nonconductor of electricity, thus capable of being used for extinguishing fire on electrical equipments. The extinguishant of the proposed fire extinguisher ( 100) has been tested to check its electrical conductivity to confirm its ability to be used for extinguishing the fire on electrical equipments by the Underwriters Laboratory (UL) standards.-

TEST:

The extinguishant of the proposed lire extinguisher ( 100) has been tested by UL standards to check the electrical conductivity.

Test Details: UL 71 1, section 9.2

Standard Condition: As per the standard the filled extinguisher should be charged with lOOkV power supply and to be discharged on earth copper plate from the distance of 10 inch. The measured discharge current should not exceed more than 1000μΑ. SR. TARGET TEST CONDITION MEASURED NO. DISTANCE DISCHARGE (IN INCH) CURRENT (IN μΑ)

1 10" At room temperature with 560

discharge for 15sec. (A.C.)

2 10" At 380°C temperature with 525

discharge forl 6sec. (A.C.)

3 10" At room temperature with 25.8

discharge for 15sec. (D.C.)

4 10" At 380°C temperature with 36.8

discharge forl8sec. (D.C.)

Conclusion: The proposed fire extinguisher ( 100) was well within the limit and the discharge current was between 25.8 to 525μΑ including target plate temperature of 380°C both for A.C and D.C power supply with maximum 16 sec discharge. Thus, the extinguishant of the proposed fire extinguisher ( 100) passes the test for electrical conductivity and thus is capable of extinguishing the fire on electrical equipment.

> The extinguishant of the proposed fire extinguisher ( 100) does not either alter the properties of objects and materials or damage the said objects and materials in the fire as it neither has residual effect nor it is reactive nor it contaminates the material involved in the fire. Thus, the said extinguishant is capable of extinguishing the fire efficiently allowing the further use of objects and materials in fire. The said material also involves flammable liquids. The extinguishant of the proposed fire extinguisher ( 100) has been tested to check its residual effect, reactivity and contamination with various objects and materials. Further, as the said extinguishant of the proposed fire extinguisher ( 100) does not leave any residue after extinguishing the fire, no cleaning is required once the fire is extinguished.

TEST:

Different types of objects and material of various industries were tested to check the residual effect, reactivity and contamination of the extinguishant of the proposed fire extinguishant ( 100) on the properties of objects and materials as below.

object /material under the fire

6 Flammable No reactivity observed with the Liquids object/material under fire and thus no.

alteration in the property of the object/material under the fire

Conclusion: Thus, the extinguishant of the proposed fire extinguisher (100) is capable of being used for extinguishing fire on different objects and material without altering the properties of objects and materials or damaging the said objects and materials in the fire as it neither has residual effect nor it is reactive nor it contaminates the material involved in the fire and enabling further use of the objects and materials in the fire.

" The extinguishant of the proposed fire extinguisher ( 100) which produces negligible amount of toxic gases compare to the conventional extinguishants.

> The shelf life of extinguishant of the proposed fire extinguisher ( 100) is at least 10 years during which the said extinguishant retains its effect intact without degradation and although after 10^th year the said extinguishant starts degrading the rate of degradation is so minimal that the said extinguishant does not affect the working of the fire extinguisher ( 100).

TYPE SOLID FLAMMABLE FLAMMABLE ELECTRICAL COOKING FIRE LIQUIDS GASES EQUIPMENT OILS AND S FATS

1 Water Yes No No No No

Foam Yes Yes No . No Yes

Dry Yes Yes Yes Yes No Powder

C02 No Yes No Yes Yes

Present Yes Yes Yes Yes Yes extinguish

er

Another major embodiment of the proposed fire extinguisher ( 100) is to provide an improved fire extinguisher ( 100) assembly as shown in Fig. 1 , Fig.2 [A, B] which mainly comprises of cylinder assembly (101) and valve assembly ( 102) whereby the

(i) Cylinder assembly (101) mainly comprises of: a cylinder ( 1) with a concave base and an opening hole at middle top having a threaded coupling on inner surface, ^' provided to fill the extinguishing agent which is a blend of extinguishing gas and proprietary gas using the expellant; a deep tube ( 19) with 10° chamfer at bottom extending through the top middle hole of the cylinder ( 1 ) and touching the cylinder ( 1 ) bottom to allow complete discharge of the extinguishant from the cylinder ( 1); a base ring at bottom of the cylinder ( 1 ) to maintain the stability to stand on the plain surface; a threaded coupling on the inner surface of the opening hole of the cylinder ( 1 ) is provided to assemble the valve assembly ( 102) over the cylinder assembly ( 101 ) and

(ii) valve assembly ( 102) is provided to discharge the extinguishant from the cylinder assembly ( 101) for extinguishing the fire, which mainly comprises of: a valve body (2) having four different connecting means namely

> lower connecting means (2A) facing lower side of the valve assembly ( 102), having

o a hole parallel to side connecting means 1 (2C) for assembling a pressure gauge ( 18) ,

o a provision for assembling male installation bracket (23) attached parallel to side connecting means 2 (2D) ,

o a threaded protrusion perpendicular to the pressure gauge ( 18), cylinder ( 1 ) and male installation bracket (23) for assembling a round handle ( 17) and

o a protruded lower end having threads for coupling with the cylinder assembly ( 101 ) in a leak proof manner,

> side connecting means 1 (2C), and side connecting means 2 (2D) facing opposite sides of the valve body (2) , upper connecting means (2 B) - facing upper side of the valve assembly ( 102) and

an extension with hole (25) for fastening a safety lock pin (20);

a pressure gauge ( 18) assembled in the hole of the lower connecting means (2A) and parallel to side connecting means 1 (2C) through a chain ring (22) for indicating the correct extinguishant pressure; a chain ring (22) assembled behind the pressure gauge ( 18) to connect and support to the one end of the chain link (21 ); a male installation bracket (23) assembled at the lower connecting means (2A) using 2 screws for mounting on female installation bracket; a round handle ( 17) assembled at the lower connecting means (2A) on threaded protrusion perpendicular to the pressure gauge ( 18), cylinder ( 1) and male installation bracket (23) to hold the fire extinguisher (100) and to provide fix support to operate the valve and to press the valve lever ( 10); a pair of Poly Tetra Fluoro Ethylene (PTFE) ball washer namely lower ball washer (3AL) and upper ball washer (3AU) each having a hole in middle and assembled inside the valve body (2); a rotating S.S. ball (4) assembled inside the valve body (2) between lower ball washer (3AL) and upper ball washer (3AU), whereby the said rotating S.S. ball (4) has a hole inside which is in non facing position with the respective hole of lower ball washer (3AL) and upper ball washer (3AU) when the valve lever ( 10) is in resting position as shown in Fig.2A whereas, on pressing the valve lever ( 10); the said rotating S.S. ball (4) rotates in a clockwise direction such that the hole of the said rotating S.S. ball (4) forms channel with the respective hole of lower ball washer (3AL) and upper ball washer (3AU) without any air gap, facilitating the path to the extinguishant to pass from the cylinder (1) to discharge pipe ( 12) via hole of lower ball washer (3AL) and upper ball washer (3AU) as shown in Fig.2B; a valve lever ( 10) which is assembled parallel and above the round handle (17) respectively through valve lever side bolt ( 1 1) at side connecting means 1 (2C) and through ball pin (6A) and nut (6B) at side connecting means 2 (2D) to rotate the S.S. ball (4) in clock wise and anticlockwise direction by respective down and up movements; a valve lever side bolt ( 1 1) to fix and support the valve lever ( 10) at side connecting means 1 (2C); a ball pin (6A) which at one end connects the S.S. ball (4) assembled inside the valve body (2) through side connecting means 2 (2D) and on other end it connects the side pin free nut (5) and nut (6B) to hold the said valve lever ( 10) firmly and to rotate the S.S. ball (4) in a clockwise direction such that the hole of the S.S. ball (4) forms channel with respective hole of lower ball washer (3AL) and upper ball washer (3AU); a pair of coil spring, one coil spring (9A) which is assembled at side connecting means 1 (2C) between the valve lever side bolt ( 1 1) and valve lever ( 10) and other coil spring (9B) assembled at side connecting means 2 (2D) between the nut (6B) and side pin free nut (5), for pushing back the valve lever ( 10) automatically to stop supply of the extinguishant by rotating the ball pin (6A) and thus S.S. ball (4) in anticlockwise direction to allow the hole of the said S.S. ball (4) to come in non facing position with the respective hole of lower ball washer (3AL) and upper ball washer (3AU) as shown in Fig.2A; a side pin washer (3B) assembled between ball pin (6A) and coil spring (9B) at side connecting means 2 (2D)) to hold them firmly to prevent the leakage; a washer (3C) assembled between ball pin (6A) and valve lever ( 10) attached at side connecting means 2 (2D) to hold them firmly to prevent the leakage; a side pin free nut (5) which is assembled at side connecting means 2 (2D) between the side pin washer (3B) and a coil spring (9B) to support the valve lever ( 10); a top nut (7) having its lower end assembled at upper connecting means (2B) through threaded coupling to facilitate the necessary pressure on both upper ball washer (3AU) and lower ball washer (3AL) allowing the S.S. ball (4) to rotate smoothly at time of extinguishing the fire and having its upper end assembled with discharge pipe ( 12), to allow the extinguishant to pass further from the upper ball washer (3AU) to discharge pipe ( 12); a top nut washer (3D) which is assembled between the top nut (7) and upper connecting means (2B) to hold them firmly to maintain the required pressure and to prevent the leakage; a discharge pipe ( 12), through threaded couplings is connected to the cap nut (8) at its upper end and to the top nut (7) at its lower end to allow the flow of extinguishant to pass through the plastic nozzle ( 13) connected to the cap nut (8) ; a cap nut (8) connected to the discharge pipe (12) at upper end and to the plastic nozzle (13) at lower end, holds the said plastic nozzle (13) properly in the nozzle cap (16) through the threaded coupling; a plastic nozzle (13) attached at upper end of the cap nut (8) as shown in Fig. l, Fig.2[A, B] and Fig.3[A, B, C, D] having

o hole at middle for allowing the deflector screw (15) to pass through for fixing the nozzle deflector (14) and

o plurality of discharge holes at periphery which evenly distribute the flow of extinguishant coming out from the discharge pipe (12) into plurality of droplets and to further strike them out on the outer surface of the nozzle deflector (14) in shower manner; a nozzle deflector (14) which is fixed to the plastic nozzle (13) using the deflecting screw (15) strikes further the plurality of droplets coming out from the plurality of discharge holes of the plastic nozzle (13) on to the nozzle cap (16) dividing the said plurality of droplets into smaller size multiple homogeneous droplets; a deflector screw (15) passing through the hole of the plastic nozzle (13) firmly holds the nozzle deflector (14) to the plastic nozzle (13); a nozzle cap (16) fixed to the cap nut (8), being conical in shape, facilitates the uniform shower of the multiple homogeneous droplets of extinguishant striking out on the inner surface of the nozzle cap (16) from the outer surface of the nozzle deflector (14) to cover the larger area of the fire in conical pattern by utilizing entirely the flow of multiple homogeneous droplets to control the fire instantaneously; a safety lock pin (20) with the chain link (21) is fastened into an extension with hole (25), provided on the valve body (2) in between and in the direction of handle (17) and valve lever (10) such that it does not allow the valve lever (10) to get pressed without disengaging it to avoid unwanted operation or tampering of the proposed fire extinguisher (100) while it is mounted on the wall; a chain link (21) having its one end connected to the safety lock pin (20) and the other end connected to chain ring (22) such that it holds and hangs the safety lock pin (20) once it is disengaged from its position for operating the fire extinguisher (100); a tamper seal (24) fasten into the safety lock pin (20) to indicate tampering with the proposed fire extinguisher (100).

The said deep tube (19) is also called siphon tube. The length of the deep tube (19) is kept such that it touches the bottom of the cylinder (1). The said deep tube (19) has chamfer of 10° at bottom such that the cross- sectional diameter of the deep tube (19) and diameter of the top nut (7) remains same allowing complete discharge of the extinguishant from the cylinder (1) to discharge pipe (12). In addition, to maintain the efficiency of the discharge of the extinguishant, the shape of the bottom of the cylinder (1) is kept 10° concave in order to expel out each drop of the extinguishant. Thus, the cylinder assembly (101) of the proposed invention is constructed in highly efficient manner which allows the utilization of total amount of extinguishant in controlling the fire by the proposed improved fire extinguisher (100).

The pressure gauge (18) of the proposed fire extinguisher (100) is pre- calibrated gauge based on the behavior of the extinguishant with reference to the atmospheric temperature difference. The said pressure gauge (18) ensures the indication of correct extinguishant pressure so that the proposed fire extinguisher (100) gets operated correctly the way it is designed and performs to extinguish the fire without any complication.

The proposed fire extinguisher (100) is mounted on the wall mounting female installation bracket through the male installation bracket (23) of the proposed fire extinguisher (100). The said female installation bracket is made out of S.S. to ensure corrosion free strong mounting on the wall using S.S. screw fittings.

The round handle (17) of the proposed fire extinguisher (100) is provided to hold the fire extinguisher (100) and to provide fix support to operate the valve and to press the valve lever (10). The said handle (17) has in built S.S. bolt. The said handle (17) being made up of bakelite is highly stable at atmospheric condition and is corrosion free. Further, the length of the S.S. bolt is almost 70% of the length of the handle (17), thus even if the said handle (17) gets broken because of high impact still the fire extinguisher (100) can be easily operated.

The said upper ball washer (3AU) and lower ball washer (3AL) are neither porous nor have any atmospheric and extinguishant effect over them. Further, the said upper ball washer (3AU) and lower ball washer (3AL) are neutral to extinguishing agent and have self lubricating property without any sticky effect. Thus, the said upper ball washer (3AU) and lower ball washer (3AL) all together provides leak proof, jam proof and smooth functioning of the valve assembly (102) of the proposed improved fire extinguisher (100). The said discharge pipe (12) being made up of S.S. has high mechanical strength and is smoothly curved to allow the easy flow of extinguishant through plastic nozzle (13). The said safety lock pin (20) is so designed that it is easy to disengage.

The multiple droplets of extinguishant striking out from the nozzle cap (16) for extinguishing the fire in form of conical flow are air pocket free homogeneous droplets. The extinguishant gets discharged out in form of uniform shower of the multiple homogeneous droplets and cover the fire base with nine to ten times more diameter than the diameter of the nozzle cap (16) to control the fire instantaneously.

The said cylinder (1), valve body (2), Lower ball washer (3AL), Upper ball washer (3AU), side pin washer (3B), washer (3C), top nut washer (3D), S.S. ball (4), side pin free nut (5), ball pin (6A), nut (6B), top nut (7), cap nut (8), coil spring (9 A) (at side connecting means 1 (2C)), coil spring (9B) (at side connecting means 2 (2D)), valve lever (10), valve lever side bolt (11), discharge pipe (12), nozzle deflector (14), deflector screw (15), nozzle cap (16), deep tube (19), safety lock pin (20), chain link (21), chain ring (22), male installation bracket (23), tamper seal (24) are made from either of the below mentioned high grades of the S.S. facilitating the corrosion free fire extinguisher (100).

9 30308 308

10 30309 309

11 30309S 309S

12 30310 310

13 30310S 310S

14 30314 314

15 30316 316

16 30316L 316L

The above list of the S.S. grades provide fire extinguisher with above mentioned characteristic features. The preferred grade of S.S. used for manufacturing the fire extinguisher to operate in a best mode is S.S.

304.

All the above said parts of both cylinder assembly (101) and valve assembly (102) altogether are assembled in a manner to provide a leak proof and highly efficient fire extinguisher (100). Further, all the above said parts of the proposed fire extinguisher (100) being made up of high grade S.S. facilitates corrosion free fire extinguisher (100) which is highly stable in undesirable atmospheric conditions and thus has a long shelf life and durability.

The extinguishant of the proposed fire extinguisher (100) is such that it can be filled and stored at a low pressure of 100 PSI enabling a thin walled cylinder to be used for manufacturing a durable fire extinguisher resulting in considerably reducing the weight of the fire extinguisher.

The proposed fire extinguisher (100) is able to be used for more than one time as it is possible to stop the expelling out of the extinguishant from the fire extinguisher (100) once the required quantity of extinguishant is expelled out for extinguishing the fire and the rest of the extinguishant can be used for extinguishing the fire another time when the fire takes place.

TESTS:

The proposed fire extinguisher was tested for its strength, durability and reliability; to check leakage and bursting. Standard tests were performed based on guidelines of Underwriters Laboratories (UL).

The key tests namely proof test and burst test are essential for assuring that the fire extinguisher is capable of withstanding high pressure and reliable in avoiding of leakage and bursting.

The details of the UL pressure tests are as under: 1) Proof Test

In the proof test the pressure maintained inside the cylinder is three times higher than working pressure of the fire extinguisher to check if leakage occurs between any of the parts of the fire extinguisher.

The working pressure of the proposed fire extinguisher (100) is 100 PSI.

2 305 60 No leakage found at any of the joints

3 307 63 No leakage found at any of the joints

The pressure maintained in cylinder (1) of the proposed fire extinguisher (100) was 300, 305 and 307PSI respectively for 61, 60 and 63 seconds to check if leakage occurs between any of the parts of the fire extinguisher (100). The results received shown even at 300PSI no leakage between any of the parts of the fire extinguisher (100). Thus the proposed fire extinguisher (100) passed the proof test.

2) Bust Test

In the bust test the pressure maintained inside the cylinder is eight times higher working pressure of the fire extinguisher to check if the cylinder busts at such high pressure and if not then leakage occurs between any of the parts of the fire extinguisher and if.

SR. NO. PRESSURE DURATION FOR RESULTS

APPLIED HOLDING THE

(PSI) PRESSURE (SEC)

1 800 60 Neither the cylinder busts nor leakage found at any of the joints

2 810 62 Neither the cylinder busts nor leakage found at any of the joints

3 815 61 Neither the cylinder busts nor leakage found at any of the joints

4 2000 400 Neither the cylinder busts nor leakage found at any of the joints

The pressure maintained inside the cylinder (1) of the proposed fire extinguisher (100) was 800, 810 and 815PSI respectively for 60, 62 and 61 seconds to check if the cylinder (I) busts at such high pressure and if not then leakage occurs between any of the parts of the fire extinguisher. The results received shown that even at high pressure of 800, 810 and 815PSI the cylinder (1) did not bust neither any leakage was found between any of the parts of the proposed fire extinguisher (100). Thus the proposed fire extinguisher (100) passed the bust test.

However we continued the test to get the reading of bust pressure. On increasing gradual pressure from 800 psi to 2000 psi where the limit of National Accreditation board for testing and calibration laboratories (NABL) calibrated equipment limit was over so we maintained the same pressure of 2000 psi inside the cylinder (1) for more than 400 seconds but still the cylinder (1) did not bust neither we observed leakage between any of the parts of the proposed extinguisher (100) except the diameter of the cylinder has increased from 107 mm to 120 mm.

This test ensures the cylinder (1) of the proposed fire extinguisher (100) does not bust even at high pressure of 2000PSI facilitating high safety factor of the fire extinguisher (100) and operator of such extinguisher avoiding all the fatal accidents.

Further, the guidelines provided by UL also suggest tests for the strength of the other parts of the extinguisher which were performed to ensure complete reliability of the fire extinguisher.

The details of the tests performed and the results obtained are as provided in the tables below:

PHASE I - TESTING:

axis shall not found between exceed 13.6kg 6.4kg to 9.8 kg with with 30 sec 30 seconds duration. duration . which is well within the range of UL standard.

Handle UL 2129, Sec 28 As per the The handle and

& standard the mounting device

Mountin handle and i.e. installation g Device mounting device bracket of the i.e. installation proposed

bracket should extinguisher was take five times found to carry the load of the total five times load of weight of the the total weight for extinguisher or more than 10

45kg whichever is minutes which is greater for 5 min well within the duration. It range of UL should not fall standard.

down.

Operatio UL 2129, Sec 29 As per the The proposed n Test standard the extinguisher was extinguisher to be held at 45° in every hold at 45° in direction and was every direction found to discharge and to be the extinguishant discharge. The 90 in the range of 90 % content should to 95 % which is discharge of its well within the rated capacity. range of UL standard.

Dischax UL 2129, Sec 30 As per the The proposed ge standard hold extinguisher was

Duratio extinguisher held vertically up n vertically up and and was the to be discharged contents were with complete found to be valve open discharged to gas condition. The point within the contents should range of 8 to 12 discharge to gas seconds which is point in well within the minimum 8 range of UL seconds. standard.

Rate of UL 2129, Sec 31 An extinguisher The proposed Flow charged with its extinguisher was rated capacity is found to be to be discharged discharging within for a period of the range of UL two-thirds of its standard.

average discharge

duration at

21±3°C (70±5°F).

Intermitt UL 2129, Sec 32 As per the The proposed ent standard 75% (by extinguisher was Dischar mass) content found to be ge should discharging the discharged. content in the range of 75 to 85 % which is well within the range of UL standard.

Operatin UL 2129, Sec 33 As per the The proposed g standard 90% (by extinguisher was

Tempera mass) content found to be ture should discharge discharging the

Limits after completion content in the of temperature range 90 to 99.90 test. % which is well within the range of UL standard.

Tempera UL 2129, Sec 34 As per the The proposed ture standard 90% (by extinguisher was

Cycling mass) content found to be should discharge discharging the after completion content in the of temperature range 90 to 99.90 cycling test % which is well within the range of UL standard.

High UL 2129, Sec 36 As per the The proposed Temperastandard the extinguisher was ture complete found retaining its Exposur extinguisher parts without e assembly rupturing when required to be kept at 79±3° C for kept at 79±3° C 7 days which is for 7 days. The well within the UL extinguisher shall standard.

retain its parts

without rupture.

Cylinder UL 2129, Sec The volumetric The proposed s 39.1

expansion of the extinguisher cylinder should cylinder was found not exceed 10% of to be expanding in the total the range of 6 to expansion after 10% of the total proof test i.e. 300 expansion at high psi. pressure of more than 800 psi which is well within the range of UL standard.

Valves UL 2129, Sec A) As per the A) The proposed

39.2 standard extinguisher extinguisher valve was found valve shall to be withstand 300 withstanding psi for one min the pressure of without 300 psi within leakage. the time limit of

1 to 5 min with no leakage observed.

B) The proposed

B) Valve various extinguisher parts shall valve was found remain in to be remaining assembled assembled when condition for exposed at minimum 1 pressure of 600 min at twice psi for 4 the proof test minutes with no i.e. 600 psi. leakage found.

One- UL 2129, Sec 48 As per the The proposed

Year standard, a extinguisher was

Time stored-pressure well within the

Leakage type extinguisher standard

shall retain its requirement. The expellant-gas pressure and charge for 1 year weight loss was in at a temperature range of 0 to 3 %. of 21 ±4°C (70

±7°F). 12

extinguishers.

Twelve sample

extinguishers

charged with

their rated

capacity are to be

tested; six in a vertical position and six in a horizontal , position and their pressure and weight checked after 1, 3, 6, and 12 months for leakage.

After 1 year no internal part exposed to the Extinguishant should get ditoriated. The pressure should not drop to the lower limit of the operable pressure range, which is 50 psi.

PHASE II - TESTING:

should be limit and the charged with discharge current lOOkV power was between 25.8 supply and to be to 525μΑ including discharged on target plate earth copper temperature of plate from the 380°C both for A.C distance of 10 & D.C power inch. The supply with measured maximum 16 sec discharge current discharge.

should not

exceed more than

1000μΑ.

Vibration UL 2129 , Sec As per the The proposed

40 standard the extinguisher was vibration of the well within the complete standard range extinguisher and discharged 90 assembly to be to 99.9%.

carried out and

on completion of

the test the

extinguisher

should discharge

90% of the

content of its

rated capacity.

Servicing UL 2129, Sec As per the The proposed standard, after extinguisher was 30 recharging found well within cycles, a the requirements rechargeable and complied with extinguisher the requirements charged with its of the Discharge rated Duration Test and capacity shall the Hydrostatic retain its charge Pressure Test. during a 24-hour

conditioning cycle

at minimum

storage and use

temperature and

then shall comply

with the

requirements of

the Discharge

Duration Test

and the

Hydrostatic

Pressure Test.

During each

cycle, the

extinguisher is to

be cleaned, filled

with agent,

pressurized, and

discharged as per

our service

manual instructions. The complete valve assembly, including discharge nozzle, stem, pressure gauge, and siphon tube assembly is to be disassembled during the first, tenth, twentieth, and thirtieth cycles. After the tenth cycle, an extinguisher having polymeric parts is to be subjected to the Aging Tests Polymeric

Materials, except that the test duration is to be reduced to 90 days at 100°C (212°F) for a valve and valve part, and 45 days at 100°C (212°F) for a siphon tube assembly and

then shall comply

with the

requirements of

the Discharge

Duration Test

and the

Hydrostatic

Pressure Test.

Road UL 2129 Sec As per the The proposed ability 41 standard the extinguisher was and charged absolutely in

Rough extinguisher working condition

Usage should be and hence dropped three according to the times from standards.

different angle i.e.

upside down,

down side up,

horizontal on one

direction so that

the cap strike on

the flour and

other side so that

the black handle

strike on the

flour. The flour

should be of

minimum 4 inch

of concrete and the drop height should be 3 ft. After the test instrument should be in operational condition and pass through proof & . rupture test.

PHASE III - TESTING:

c shall be no nozzle, PTFE

Material cracking of a washer after air s polymeric valve, oven aging for 180 valve parts, days at 100±3°C gauge / indicator were found intact components, in working cylinder, condition. There or bracket after was no cracking or air-oven aging for misshape

180 days at 100 observed.

±3°C (212 ±5°F).

Exposur UL 2129, Sec As per the The component e to 43.2 standards, all the parts of the extingui components of proposed

shing extinguisher that extinguisher were agent remains in continuously

contact with tested for more contact with the than a year extinguishant exposing to the should be free proposed

from crack, melt, extinguishant and corrosion, all the parts were misshape. found absolutely intact and in working condition.

Salt UL 2129, Sec 45 As per the The proposed

Spray standards, the extinguisher is well

Corrosio fire extinguisher within the n must be requirement and operational and found to be rechargeable even corrosion free and after all parts of could be easily the extinguisher, operated and including the recharged.

finishes on coated

or painted parts,

the assemblies of

moving parts, the

nameplates as

secured in place,

and brackets or

mounting hooks,

are be subjected

to a 240 hour salt

spray exposure.

Therefore, based on the tests performed and the results obtained, it is found that the proposed extinguisher is durable and completely reliable.

WORKING OF INVENTION

As shown in Fig.1 and Fig.2[A&B] an improved fire extinguisher (100) is mounted on the wall mounting female installation bracket by sliding in the inbuilt male installation bracket (23) of the proposed fire extinguisher (100). In order to extinguish the fire, the proposed fire extinguisher (100) has to be slide out from the female installation bracket using a round handle (17). In order to operate the said fire extinguisher (100) first of all safety lock pin (20) fastened into an extension with hole (25) has to be taken out which breaks the tamper seal and allows an operator of fire extinguisher (100) to press the valve lever (10). On pressing the valve lever (10), a ball pin (6A) holding the valve lever (10) firmly at side connecting means 2 (2D) rotates. As the ball pin (6A) rotates, the rotating S.S. ball (4) which is further connected to the said ball pin (6A) rotates in clockwise direction such that the hole of the rotating S.S. ball (4) forms channel with the respective hole of lower ball washer (3AL) and upper ball washer (3AU) without any air gap as shown in Fig.2[B], facilitating the path to the extinguishant to pass from the cylinder (1) to discharge pipe (12) via hole of lower ball washer (3AL) and upper ball washer (3AU). Further from the discharge pipe (12), the extinguishant passes to the plastic nozzle (13) connected via the cap nut (8). The said plastic nozzle (13) due to the plurality of discharge holes provided at periphery as shown in Fig.3[A, B, C, D] evenly distribute the flow of extinguishant coming out from the discharge pipe (12) into plurality of droplets and further strike them out on the outer surface of the nozzle deflector (14) in shower manner. The said nozzle deflector (14) which is connected to the said plastic nozzle (13) through the deflector screw (15) strikes further the plurality of droplets coming out from the plurality of discharge holes of the plastic nozzle (13) on to the nozzle cap (16) dividing the said plurality of droplets into smaller size multiple homogeneous air pocket free droplets. The nozzle cap (16) fixed to the cap nut (8), being conical in shape, facilitates the conical flow of the homogeneous uniform discharge shower of the multiple droplets striking out on the inner surface of the nozzle cap (16) from the outer surface of the nozzle deflector (14) to cover the larger area of the fire by utilizing entirely the flow of multiple homogeneous droplets to control the fire instantaneously. Once the fire is extinguished the valve lever (10) automatically achieves the resting position as shown in Fig.2 [A] due to the coil spring (9A and 9B). The said coil spring (9A and 9B) on leaving the valve lever (10) rotates the ball pin (6A) and thus S.S. ball (4) connected with the said ball pin (6A) in anticlockwise direction to allow the hole of the said S.S. ball (4) to come in non facing position with the respective hole of lower ball washer (3AL) and upper ball washer (3AU) as shown in Fig.2 [A] to stop supply of the extinguishant. After the use, the fire extinguisher (100) can be again mounted on the wall mounting female installation bracket by sliding in the inbuilt male installation bracket (23) of the proposed fire extinguisher (100) and can be used further in the same manner for multiple times till the total content of extinguishant expels out. Once, the total content of extinguishant expels out the cylinder (1) can be refilled and used again in the same manner.

ADVANTAGES OF THE PRESENT INVENTION

The proposed invention imparts following advantages over the different types of fire extinguishers available in the market:

• The present improved fire extinguisher extinguishes almost all types of fire and hence there no confusion to the operator to select the appropriate type of extinguisher suitable to the type of material involved in the fire.

• Easy to operate

• Extinguishant is filled and maintained inside the cylinder at quite lower pressure of 100PSI. Facilitates the conical shape shower of multiple droplets of extinguishant for extinguishing the large area of fire base instantaneously.

It does not have residual effect and hence does not require cleaning after extinguishing the fire.

Extinguishing fire using the present extinguisher does not alter the properties of the material in the fire, enabling them to be used further.

Extinguishing fire using the present extinguisher does not damage the objects and material on the fire.

Extinguishing fire using the present extinguisher does not contaminate the objects and material on the fire.

The extinguishant used in the present invention is not a conductor of electricity and so there are no risks of fatal accidents like electric shocks and hence can be used to extinguish electrical fires also.

The extinguishant used in the present invention is able to extinguish fire on flammable gases as well as flammable liquids.

The extinguishant used in the present invention is able to extinguish fire on cooking oils & fats and alike without contaminating the material involved in the fire.

It contains extinguishant that has a long shelf life.

It contains extinguishant that does not have problems of discharge visibility. There are no risks of cold burns to the operator of the proposed extinguisher.

The proposed fire extinguisher completely expels out extinguishant.

The extinguishant from the extinguisher cuts off the oxygen supply to the fire and hence extinguishes the fire.

The proposed extinguisher can be used for more than one time as it is possible to stop the expelling out of the extinguishant from the extinguisher as soon as fire is extinguished.

There is no risk of splashing off of the extinguisher from the operators hand or of bursting.

There is no risk of injury to the operator.

The present fire extinguisher prevents all the problems associated with corrosion.

It is made up of S.S. and hence there are no problems of breakage due to corrosion.

In the present extinguisher, the safety lock pin is made of S.S. which has a high metal strength and no risks of corrosion so that it does not break easily and is easy to disengage when required.

The present extinguisher has installation brackets made of S.S. which withstands the weight of the fire extinguisher and does not get corroded. The present invention is completely leak proof and hence serves the purpose of fire extinguishing when required.

It involves extinguishant filled with low pressure that eliminates the problems of leakage, splashing off and bursting.

The low pressure extinguishant filled in the present extinguisher does not require thick walled cylinders and hence make the extinguisher light weight.

The present extinguisher consists of S.S. ball which prevents leakage and has longer shelf life and making the valve assembly the extinguisher durable.

Deep tube of the proposed extinguisher is made of S.S. and hence has a high durability and there are no risks of bends, cracks or breakage because of pressure.

The deep tube of the proposed extinguisher have chamfered cut at the bottom at around 10° that does not leave behind unused extinguishant after complete discharge which enhances the efficiency of extinguishing the fire.

In the proposed extinguisher, the bottom ring is made up of S.S. and assembled in a manner to prevent leakage even if it falls.

The present extinguisher consists of a nozzle with multiple holes facilitating shower type of discharge of the extinguishant avoiding splashing of fire and hence controls the spreading of fire.

The discharge pipe of the present extinguisher is made of S.S. and so has a higher mechanical strength, efficiency and life to withstand climatic conditions such as sunlight, rain water, cold and hot air, air pollution like petroleum, solvent or chemical fumes and hence does not get cracked or broken serving its the purpose when required.

The present extinguisher uses a standard calibrated pressure gauge which is calibrated in reference to the extinguishant used in the present extinguisher, and thus indicates the right designed pressure avoiding the problems associated with the working of the extinguisher such as splashing of the material on fire, leakage, metal fatigue and other problems related to valve operation.

The generation of toxic gases is negligible.

Claims

1. An improved fire extinguisher (100) characterized in which the composition of extinguishant of the proposed fire extinguisher (100) comprises of:

> 2,2-Dichloro-l,l, l-trifluoroethane in proportion range of 90 to 95%, > Tetrafluoromethane in proportion range of 3 to 6% and

> Argon gas in proportion range of 1.5 to 3.5%.

2. An improved fire extinguisher (100) as claimed in claim 1 characterized in which, the preferable proportion of the said 2,2-Dichloro-l, l, l- trifluoroethane is 93.1%.

3. An improved fire extinguisher (100) as claimed in claim 1 characterized in which, the preferable proportion of the said Tetrafluoromethane is 4.3%.

4. An improved fire extinguisher (100) as claimed in claim 1 characterized in which, the preferable proportion of the said argon gas is 2.6%.

5. An improved fire extinguisher (100) as claimed in claim 1 characterized in which, the boiling point of the extinguishant is 25.5°C ( 81.7 F ) at 760 mmHg.

6. An improved fire extinguisher (100) as claimed in claim 1 characterized in which, the extinguishant is volatile in nature.

7. An improved fire extinguisher (100) as claimed in claim 1 characterized in which, the vapour density of the extinguishant is 6.07kg/m3.

8. An improved fire extinguisher (100) as claimed in claim 1 characterized in which, the extinguishant has shelf life of at least 10 years. 9. An improved fire extinguisher (100) as claimed in claim 1 characterized in which, the extinguishant does not either alter the properties of objects and materials or damages the said objects and materials in the fire as it neither has residual effect nor it is reactive nor it contaminates the material involved in the fire.

10. An improved fire extinguisher (100) as claimed in claim 1 characterized in which, the extinguishant is nonconductor of electricity.

11. An improved fire extinguisher (100) as claimed in claim 1 characterized in which, the extinguishant when discharge out from the fire extinguisher

(100) is in liquid form and rapidly gets converted into gaseous form.

12. An improved fire extinguisher (100) as claimed in claim 1 characterized in which, the extinguishant is filled and stored inside the cylinder (1) at lower pressure of 100PSI.

13. An improved fire extinguisher (100) as claimed in claim 1 characterized in which, the extinguishant produces negligible amount of toxic gases.

14. An improved fire extinguisher (100) characterized in which fire extinguisher (100) assembly mainly comprises of cylinder assembly (101) and valve assembly (102) whereby the

(i) Cylinder assembly (101) mainly comprises of: a cylinder (1) with a concave base and an opening hole at middle top having a threaded coupling on inner surface, provided to fill the extinguishing agent which is a blend of extinguishing gas and proprietary gas using the expellant; a deep tube (19) with 10° chamfer at bottom extending through the top middle hole of the cylinder (1) and touching the cylinder (1) bottom to allow complete discharge of the extinguishant from the cylinder ( 1 ) ; a base ring at bottom of the cylinder (1) to maintain the stability to stand on the plain surface; a threaded coupling on the inner surface of the opening hole of the cylinder (1) is provided to assemble the valve assembly (102) over the cylinder assembly (101) and

(ii) valve assembly (102) is provided to discharge the extinguishant from the cylinder assembly (101) for extinguishing the fire, which mainly comprises of: a valve body (2) having four different connecting means namely

> lower connecting means (2A) facing lower side of the valve assembly

(102), having

o a hole parallel to side connecting means 1 (2C) for assembling a pressure gauge (18),

o a provision for assembling male installation bracket (23) attached parallel to side connecting means 2 (2D),

o a threaded protrusion perpendicular to the pressure gauge (18), cylinder (1) and male installation bracket (23) for assembling a round handle (17) and

o a protruded lower end having threads for coupling with the cylinder assembly (101) in a leak proof manner, > side connecting means 1 (2C), and side connecting means 2 (2D) facing opposite sides of the valve body (2),

> upper connecting means (2B) facing upper side of the valve assembly ( 102) and

> an extension with hole (25) for fastening a safety lock pin (20); a pressure gauge (18) assembled in the hole of the lower connecting means (2A) and parallel to side connecting means 1 (2C) through a chain ring (22) for indicating the correct extinguishant pressure; a chain ring (22) assembled behind the pressure gauge (18) to connect and support to the one end of the chain link (21); a male installation bracket (23) assembled at the lower connecting means (2A) using 2 screws for mounting on female installation bracket; a round handle (17) assembled at the lower connecting means (2A) on threaded protrusion perpendicular to the pressure gauge (18), cylinder (1) and male installation bracket (23) to hold the fire extinguisher (100) and to provide fix support to operate the valve and to press the valve lever (10); a pair of Poly Tetra Fluoro Ethylene (PTFE) ball washer namely lower ball washer (3AL) and upper ball washer (3AU) each having a hole in middle and assembled inside the valve body (2); a rotating S.S. ball (4) assembled inside the valve body (2) between lower ball washer (3AL) and upper ball washer (3AU), whereby the said rotating S.S. ball has a hole inside which is in non facing position with the respective hole of lower ball washer (3AL) and upper ball washer (3AU) when the valve lever (10) is in resting position as shown in Fig.2A whereas, on pressing the valve lever (10), the S.S. ball (4) rotates in a clockwise direction such that the hole of the S.S. ball (4) forms channel with the respective hole of lower ball washer (3AL) and upper ball washer (3AU) without any air gap, facilitating the path to the extinguishant to pass from the cylinder (1) to discharge pipe (12) via hole of lower ball washer (3AL) and upper ball washer (3AU) as shown in Fig.2B; a valve lever (10) which is assembled parallel and above the round handle ( 17) respectively through valve lever side bolt (1 1) at side connecting means 1 (2C) and through ball pin (6A) and nut (6B) at side connecting means 2 (2D) to rotate the S.S. ball (4) in clock wise and anticlockwise direction by respective down and up movements; a valve lever side bolt (1 1) to fix and support the valve lever ( 10) at side connecting means 1 (2C); a ball pin (6A) which at one end connects the S.S. ball (4) assembled inside the valve body (2) through side connecting means 2 (2D) and on other end it connects the side pin free nut (5) and nut (6B) to hold the said valve lever (10) firmly arid to rotate the S.S. ball (4) in a clockwise direction such that the hole of the S.S. ball (4) forms channel with respective hole of lower ball washer (3AL) and upper ball washer (3AU); a pair of coil spring, one coil spring (9A) which is assembled at side connecting means 1 (2C) between the valve lever side bolt (1 1) and valve lever ( 10) and other coil spring (9B) assembled at side connecting means 2 (2D) between the nut (6B) and side pin free nut (5), for pushing back the valve lever (10) automatically to stop supply of the extinguishant by rotating the ball pin (6A) and thus S.S. ball (4) in anticlockwise direction to allow the hole of the said S.S. ball (4) to come in non facing position with the respective hole of lower ball washer (3AL) and upper ball washer (3AU) as shown in Fig.2A; a side pin washer (3B) assembled between ball pin (6A) and coil spring (9B) (at side connecting means 2 (2D)) to hold them firmly to prevent the leakage; a washer (3C) assembled between ball pin (6A) and valve lever ( 10) attached at side connecting means 2 (2D) to hold them firmly to prevent the leakage; a side pin free nut (5) which is assembled at side connecting means 2 (2D) between the side pin washer (3B) and a coil spring (9B) to support the valve lever (10); a top nut (7) having its lower end assembled at upper connecting means (2B) through threaded coupling to facilitate the necessary pressure on both upper ball washer (3AU) and lower ball washer (3AL) allowing the S.S. ball (4) to rotate smoothly at time of extinguishing the fire and having its upper end assembled with discharge pipe (12), to allow the extinguishant to pass further from the upper ball washer (3AU) to discharge pipe (12); a top nut washer (3D) which is assembled between the top nut (7) and upper connecting means (2B) to hold them firmly to maintain the required pressure and to prevent the leakage; a discharge pipe (12), through threaded couplings is connected to the cap nut (8) at its upper end and to the top nut (7) at its lower end to allow the flow of extinguishant to pass through the plastic nozzle (13) connected to the cap nut (8); a cap nut (8) connected to the discharge pipe (12) at upper end and to the plastic nozzle (13) at lower end, holds the said plastic nozzle (13) properly in the nozzle cap ( 16) through the threaded coupling; a plastic nozzle (13) attached at upper end of the cap nut (8) as shown in Fig. l, Fig.2[A, B] and Fig.3[A, B, C, D] having, o hole at middle for allowing the deflector screw (15) to pass through for fixing the nozzle deflector (14) and

o plurality of discharge holes at periphery which evenly distribute the flow of extinguishant coming out from the discharge pipe (12) into plurality of droplets and to further strike them out on the outer surface of the nozzle deflector ( 14) in shower manner; a nozzle deflector (14) which is fixed to the plastic nozzle (13) using the deflecting screw ( 15) strikes further the plurality of droplets coming out from the plurality of discharge holes of the plastic nozzle ( 13) on to the nozzle cap (16) dividing the said plurality of droplets into smaller size multiple homogeneous droplets; a deflector screw (15) passing through the hole of the plastic nozzle (13) firmly holds the nozzle deflector (14) to the plastic nozzle (13); a nozzle cap (16) fixed to the cap nut (8), being conical in shape, facilitates the uniform shower of the multiple homogeneous droplets of extinguishant striking out on the inner surface of the nozzle cap (16) from the outer surface of the nozzle deflector (14) to cover the larger area of the fire in conical pattern by utilizing entirely the flow of multiple homogeneous droplets to control the fire instantaneously; a safety lock pin (20) with the chain link (21) is fastened into an extension with hole (25), provided on the valve body (2) in between and in the direction of handle (17) and valve lever (10) such that it does not allow the valve lever (10) to get pressed without disengaging it to avoid unwanted operation or tampering of the proposed fire extinguisher ( 100) while it is mounted on the wall; a chain link (21) having its one end connected to the safety lock pin (20) and the other end connected to chain ring (22) such that it holds and hangs the safety lock pin (20) once it is disengaged from its position for operating the fire extinguisher (100); a tamper seal (24) fasten into the safety lock pin (20) to indicate tampering with the proposed fire extinguisher (100).

15. An improved fire extinguisher (100) as claimed in claim 14 characterized in which, deep tube (19) has chamfer of 10° at bottom such that the cross-sectional diameter of the deep tube (19) and diameter of the top nut (7) remains same allowing complete discharge of the extinguishant from the cylinder (1) to discharge pipe ( 12).

16. An improved fire extinguisher ( 100) as claimed in claim 14 characterized in which, the cylinder (1) is kept 10° concave in order to expel out each drop of the extinguishant.

17. An improved fire extinguisher (100) as claimed in claim 14 characterized in which, the pressure gauge (18) is pre- calibrated gauge based on the behavior of the extinguishant with reference to the atmospheric temperature difference.

18. An improved fire extinguisher (100) as claimed in claim 14 characterized in which, is the handle (17) made up of bakelite.

19. An improved fire extinguisher (100) as claimed in claim 14 characterized 5 in which, the handle (17) has in built S.S. bolt of 70% length of the handle (17).

20. An improved fire extinguisher (100) as claimed in claim 14 characterized in which, the upper ball washer (3AU) and lower ball washer (3AL) are

10 neither porous nor have any atmospheric and extinguishant effect over them.

21. An improved fire extinguisher (100) as claimed in claim 14 characterized in which, the upper ball washer (3AU) and lower ball washer (3AL) are

15 neutral to extinguishing agent and have self lubricating property without any sticky effect.

22. An improved fire extinguisher (100) as claimed in claims 1 and 14 characterized in which, the multiple droplets of extinguishant striking out

20 from the nozzle cap (16) for extinguishing the fire in form of conical flow are air pocket free homogeneous droplets.

23. An improved fire extinguisher (100) as claimed in claims 1 and 14 characterized in which, the extinguishant gets discharged out in form of

25 uniform shower of the multiple homogeneous droplets and covers the fire base with nine to ten times more diameter than the diameter of the nozzle cap (16) to control the fire instantaneously by cooling and cutting off the oxygen supply.

3024. An improved fire extinguisher (100) as claimed in claim 14 characterized in which, the cylinder (1), valve body (2), Lower ball washer (3AL), Upper ball washer (3AU), side pin washer (3B), washer (3C), top nut washer (3D), S.S. ball (4), side pin free nut (5), ball pin (6A), nut (6B), top nut (7), cap nut (8), coil spring (9 A) (at side connecting means 1 (2C)), coil spring (9B) (at side connecting means 2 (2D)), valve lever (10), valve lever side bolt (1 1), discharge pipe (12), nozzle deflector (14), deflector screw (15), nozzle cap (16), deep tube (19), safety lock pin (20), chain link (21), chain ring (22), male installation bracket (23), tamper seal (24) are made from either of the S.S. 301 , S.S. 302, S.S. 302B, S.S. 303, S.S. 303Se, S.S. 304, S.S. 304L, S.S. 305, S.S. 308, S.S. 309, S.S. 310, S.S. 310S, S.S 314, S.S. 316, S.S. 316L high grades of the S.S. facilitating the corrosion free fire extinguisher (100).

An improved fire extinguisher (100) as claimed in claims 14 and 24 characterized in which, the preferred grade of S.S. for manufacturing the fire extinguisher to operate in a best mode is S.S. 304.