AU6789498A - Safety excess flow valve system with adjustable closing flow rate settings - Google Patents

Description

SAFETY EXCESS FLOW VALVE SYSTEM WITH ADJUSTABLE CLOSING FLOW RATE SETTINGS

Background of the Invention

I. Field of the Invention

The present invention relates generally to the field of excess flow valves used to

regulate and prevent excess flow of fluid or gas therethrough. More particularly, the present

invention relates to excess flow valves which prevent the flow of fluid or gas through a port

if the flow rate exceeds a predetermined threshold level.

II. Description of the Related Art

The use of excess flow valves is fairly standard in the gas industry. These valves are

commonly used in gas delivery systems. The valves are intended to regulate the flow of

gas, vapor, or fluid therethrough by limiting the flow rate to a predetermined maximum rate.

If the flow rate exceeds the predetermined rate, indicating a malfunction or dangerous

condition, such as in the event of damage or rupture of a hose, pipe or fitting, the valve will

shut down the flow of fluid or gas automatically to prevent excessive discharge of the fluid

or gas.

Typically, a gas supply system comprises a bottle or utility gas line, or other high

pressure gas source, connected directly or through a pipe, or similar gas delivery means, to a

regulator unit. The regulator unit supplies the gas at a low pressure rate to its final

destination — e_^ . a kitchen oven. The excess flow valve is typically placed at the low-

pressure end of the regulator unit. The purpose of the excess flow valve is to interrupt the

gas supply should a failure occur in the pressure regulator, or in any of the connecting parts

such as a hose or pipe.

A typical excess flow valve comprises a sliding poppet inside a chamber capable of

closing an opening in the chamber, and preventing the flow of fluid or gas therethrough. A spring is often used to urge the poppet to its open position away from the opening. As the

flow rate reaches or exceeds the maximum rate, such as the rate allowed by the size of the

opening and/or spring tension, the increase in pressure differential causes the poppet to slide

toward the opening, against the tension of the spring, to regulate or close the valve. The

difficulty, however, of using standard excess flow valves is that they cannot be adjusted and

therefore cannot be used where the fluid or gas supply pressures and threshold flow rates may vary, without changing the valve.

Certain types of externally adjustable valve systems have been used in the past to

enable systems to be adjusted to different flow rates and pressures without having to

substantially replace critical components each time an adjustment is made. Such adjustment

capabilities are designed to alleviate the difficulty of having to replace internal components,

such as the spring, or change the size of the opening, each time different flow rates and

pressures are encountered. These adjustable valve systems, however, have not been

altogether satisfactory, in that they are not specifically designed to provide a wide range of

adjustments, nor to allow the valves to be precisely set in circumstances where sensitivity to

pressure changes might be needed.

An excess flow valve having limited adjustment capability is disclosed in the

Sumner et al. patent, U.S. Pat. No. 3,807,442 (the "Sumner patent"). The Sumner patent

provides an excess-flow check valve comprising a poppet member and a retainer member

with an external adjustment capability. The distance between the poppet member and an

orifice determines the flow area for the fluid passing through the valve. By varying the flow

area, the differential pressure established by the fluid flow therethrough varies inversely

(i.e., as the flow area decreases, the differential pressure increases). In one embodiment, the

Sumner patent employs a cam member which, upon rotation, adjusts the distance between its poppet member and an orifice. The ability to adjust said distance, however, is limited by

the preselected settings provided on the cam member, i.e., lobes and flats. That is, for any

given application, the shut off rate determined by the cam member might be much greater

than the combined requirements of the appliances connected to the gas line, which could

allow substantial dangerous flow to occur without actuation of the valve. The valve also

fails to accommodate for a wide range of flow rate levels which might be needed.

Another type of externally adjustable valve referred to as a velocity fuse for a

hydraulic line is shown in the Maldavs patent, U.S. Patent No. 4,383,549 (the "Maldavs

patent"). The Maldavs fuse includes a poppet valve assembly having an adjustment screw

extending into an internal shielded body. The shielded body helps to divert the flow of fluid

away from the poppet body so that only the poppet head is exposed to the fluid flow. The

internal components of the shielded body also help to dampen the movement of the poppet

so that it does not react quickly to slight changes in line pressure such as those created by

short term surges. An adjustment screw used in conjunction with a dampened poppet does

not normally provide much sensitivity to flow pressure changes.

In view of the limitations of the prior art, the excess flow valves disclosed in Sumner

and Maldavs, and other similar valves, exhibit only a limited or crude adjustment capability.

In Sumners, for example, the sensitivity of the valve depends on limited preset threshold

flow rate levels, and in Maldavs, the adjustment screw moves laterally and rotates against a

freely rotating poppet which makes precise adjustments difficult. These excess flow valves

also fail to accommodate for a wide range of flow rate levels. Accordingly, there is a need

for an excess flow valve which is sensitive to virtually any desired threshold flow rate.

Moreover, the threshold flow rate for such excess flow rate valves should be easily

adjustable to accommodate for a wide range of fluid or gas supply pressure. Summary of the Invention

The present invention provides an excess flow rate valve system and method for

regulating the flow of fluid, vapor or gas therethrough. According to the present invention,

the excess flow rate valve is adjustable to actuate within a wide range of flow rates. The

valve system is designed to shut down the flow of the fluid, vapor, or gas if the flow rate

exceeds a predetermined flow rate (the "Threshold Rate"). The valve system is responsive

to virtually any Threshold Rate, thereby accommodating a wide range of fluid or gas supply

pressure. At the same time, the valve system is precisely and accurately adjustable within

said wide range such that it can be applied to virtually any application, such as low pressure

applications, where extreme sensitivity to pressure changes might be needed. Moreover, the

valve system prevents the flow of the fluid or gas in the event of a break in a fuel line, hose,

or pipe resulting from a catastrophic event such as an earthquake, flood, explosion, or a

similar event. In such an event, the excess flow valve system shuts down the supply of fluid

or gas substantially completely, except for a minimal allowable back pressure. The valve

system will not restore the flow of the fluid or gas until the break in the fuel line, hose, or

pipe is repaired.

The preferred embodiment of the present invention relates to an excess flow valve

which prevents the flow of gas, such as natural gas, and other vapors, through a port if the

flow rate exceeds the predetermined threshold level. While the valve can be used in

conjunction with fluids, the preferred embodiment of the present valve is specifically

intended to be used to prevent excess flow of natural gas and/or liquid petroleum gas vapors

through a pipe or similar gas delivery means under low pressure in the event of a leak or

catastrophic failure. The preferred valve comprises a sliding poppet within a chamber which can be

actuated to close an orifice when the flow rate exceeds the threshold level. The orifice

allows the flow of gas from one end to another. A coiled spring is used to urge the poppet

away from the orifice under flow rates that are less than the excess level. An adjustment

mechanism is provided for setting the maximum distance the poppet can travel in relation to

the orifice. By precisely controlling the position of the adjustment mechanism, it is possible

to accurately adjust the threshold level without having to change the tension of the spring,

modifying the orifice size, or the like. At the same time, the repeatability of the valve's

operation at the desired rates is provided.

The adjustment mechanism comprises a threaded member extending through the

chamber and an adjustment cam located thereon. The threaded member is externally

adjustable and preferably perpendicular to the longitudinal travel direction of the poppet.

The cam is provided on the threaded member and can be moved laterally in relation to the

chamber and longitudinally in relation to the threaded member. On the cam is an angled

engagement surface adapted to slide in relation to a similarly angled engagement surface on

the poppet top. By turning the threaded member and moving the cam laterally, therefore,

the adjustment cam's engagement surface slides against the poppet's engagement surface,

and, by virtue of the spring urging the poppet toward the cam, causes the poppet to move

either toward or away from the orifice. The pressure applied by the spring urges the

poppet's engagement surface toward the cam's engagement surface, wherein the cam retains

the poppet's movement and determines the maximum travel distance thereof.

The spring keeps the poppet in its open position against the cam until the flow rate

exceeds the threshold level, in which case the increase in pressure differential acts upon and

causes the poppet to move to its closed position. Precisely controlling the maximum travel distance of the poppet in relation to the orifice, i.e., the Threshold Rate, enables the valve to

be substantially infinitely adjustable within its operating range and highly sensitive to flow

rate changes and pressure differentials from one part of the system to another. Also, in the

preferred embodiment, the valve is configured to substantially limit the rotation of the

poppet in relation to the cam, thereby helping to keep the angled engagement surfaces in

contact with each other, and movable unidirectionally and parallel relative to one another.

The top of the poppet is also provided with support arms that extend to the walls of the

chamber to stabilize the poppet during adjustment, i.e., turning the threaded member places

lateral pressure on the poppet top, while allowing the poppet to slide longitudinally within

the chamber.

In addition to the adjustment mechanism discussed above, several other features help

to broaden the possible range of threshold levels. First, spacers can be provided to adjust

the distance the spring can be compressed for any given travel distance between the poppet

and orifice. Second, the threaded member can be adapted to be positioned on multiple fixed

settings located on the valve housing so that the distance between the adjustment

mechanism and orifice can be varied. These pre-selected settings enable the adjustment

mechanism to be positioned either closer or further away from the orifice, thereby

expanding the range of potential threshold rates. The length of the poppet can also be varied

to expand the range if needed. The valve also contemplates using a tamper resistant break-

away plug to cover the head of the threaded member after the setting is made. After the

threaded member is turned and the proper adjustments are made to set the threshold flow

rate, the plug can be used to cover the head to prevent unauthorized adjustments. Brief Description of the Drawings

The above and other aspects, features and advantages of the present invention will be

more apparent from the Detailed Description of the Invention section presented in

conjunction with the following drawings, in which:

FIGURE 1 shows a longitudinal cross-section of an exemplary configuration of the

body of the excess flow valve used in the present invention;

FIGURE 2 shows a longitudinal cross-section of an exemplary configuration of the

excess flow valve of the present invention in its open position, wherein the cross-section is

normal to the cross-section of Figure 3;

FIGURE 3 shows a longitudinal cross-section of an exemplary configuration of the

excess flow valve of the present invention in its closed position, wherein the cross-section is

normal to the cross-section of Figure 2;

FIGURES 4a, 4b and 4c show a top view, side view and bottom view, respectively, of

an exemplary configuration of a poppet with an angled engagement surface and support

arms used in the excess flow valve of the present invention;

FIGURES 5a, 5b and 5c show an end view, top view and side view, respectively, of

an exemplary configuration of an adjustment cam with an angled engagement surface used

in the excess flow valve of the present invention;

FIGURES 6a and 6b show a side view and end view, respectively, of an exemplary

configuration of a threaded member used in the excess flow valve of the present invention;

FIGURES 7a shows a cross-section view of an exemplary configuration of a cap with

a bore on the valve body with a break-away plug used in the excess flow valve of the

present invention; FIGURES 7b shows a cross-section view of an exemplary configuration of a sealing cap used in the excess flow valve of the present invention;

FIGURES 8a and 8b show spacers of various widths that can be used in the excess flow valve of the present invention;

FIGURE 9 shows an exemplary assembly having multiple settings with a long poppet

and threaded member in the upper setting used in the excess flow valve of the present

invention;

FIGURE 10 shows an exemplary assembly having multiple settings with a long

poppet, threaded member in the upper setting and one spacer used in the excess flow valve of the present invention;

FIGURE 11 shows an exemplary assembly having multiple settings with a long

poppet, threaded member in the upper setting and two spacers used in the excess flow valve

of the present invention;

FIGURE 12 shows an exemplary assembly having multiple settings with a short

poppet and threaded member in the center setting used in the excess flow valve of the

present invention;

FIGURE 13 shows an exemplary assembly having multiple settings with a short

poppet, threaded member in the center setting and one spacer used in the excess flow valve

of the present invention; and

FIGURE 14 shows an exemplary assembly having multiple settings with a short

poppet and threaded member in the lower setting used in the excess flow valve of the

present invention. Detailed Description of the Preferred Embodiment

With reference now to the drawings, the present invention provides an excess flow

valve system and method to regulate the flow of fluid, vapor, or gas therethrough. In the

first embodiment, the valve system comprises a single-chamber housing body 1 , as shown

in Figure 1, having an upstream end 2 and downstream end 3, wherein inside the housing

body is a chamber 4 with an orifice 5 at one end. The orifice 5 is formed in a narrow

portion 7 of the housing body 1 through which fluid or gas can pass from one end 2 to the

other 3. The narrow portion 7 has a receiving portion 8 adjacent the wider portion 9 of the

chamber 4 for receiving the poppet seat 15, as will be discussed. The body 1 is preferably

externally threaded on each end 2 and 3 so that it can be secured to a threaded pipe system,

such as those used in gas distribution systems.

The body 1 has an opening or bore 10 through which a threaded member 31, as

shown in Figure 6a, can be inserted laterally into the chamber. In other embodiments,

multiple bores 10 can be provided, as will be discussed, to enable the location of the

threaded member 31 in relation to the body 1 to be changed. Directly on the other side of

the chamber 4 on the inside wall of the wider portion 9, as shown in Figure 1, is a notch 29

associated with the bore 10 such that the threaded member 31 can be extended through the

chamber 4 and into the notch to secure the member to both sides of the body 1. It should

be appreciated that other means for supporting the threaded member 31 can be used that

are within the contemplation of the present invention. The housing body 1 is preferably

made of a strong, rigid, airtight material such as steel, composite material, hardened

plastic, etc., and can be manufactured in any conventional manner.

Within the chamber 4, as shown in Figures 2 and 3, is a sliding poppet 11 and a

coiled spring 25 extending in the longitudinal direction in relation to the axis of the housing body 1. The poppet 11 and spring 25 are preferably co-axially oriented within the

chamber 4 with the spring preferably on the outside near the perimeter of the chamber and

the poppet extending relatively inside the spring. The inside wall of the chamber 4 is

preferably cylindrical to allow the spring and poppet within the chamber 4 to slide without

obstruction. The spring 25 is preferably situated in the chamber 4 such that its lower end

30 is pressed against the narrow portion 7 of the chamber 4 and its upper end 28 extends

toward the poppet top 14. The upper end 28 of the spring 25 preferably cooperates with

the poppet top 14, such that the spring urges the poppet 11 away from the orifice 5. The

spring 25 can be any conventional type, i.e., made of metal, and can be provided with a

pre-calibrated tension, as is known in the art.

The poppet 11 is generally configured to slide within the chamber 4, preferably

inside the spring 25. The poppet 11, shown in Figures 4a, 4b and 4c, preferably has a

lower flange portion 12 with four fins 16 extending therefrom, a valve seat 15 adapted to

seal the orifice 5, an extended shaft portion 13, and a poppet top 14. The lower flange

portion 12 is adapted to slide within the orifice 5 and be positioned in relation to the

chamber so that the poppet 11 can slide in a longitudinal direction guided by the fins 16.

The poppet seat 15 extends outward at the top of the flange portion 12 and is preferably

configured to substantially mate with the receiving portion 8 such that, in its closed

position, as shown in Figure 3, the poppet seat 15 seals the orifice 5. The spaces 18

between the fins 16, as shown in Figure 4c, as well as the distance between the poppet seat

15 and the orifice's receiving portion 8, help determine the flow area through which the

fluid or gas can pass from one end 2 to the other 3. The size of the orifice 5, as well as the

flow area 18 between the fins 16, therefore, are carefully calibrated to provide the

appropriate amount of flow. Above the seat 15 is the shaft portion 13 which is preferably relatively thin to reduce the overall weight of the poppet so that gravity does not

substantially affect the performance of the valve. Ribs 24 can be provided along the shaft

portion 13 to provide rigidity if desired. By lengthening or shortening the shaft portion 13,

or other portions of the poppet, the poppet 11 can be made either longer or shorter, to

adjust the threshold flow rate, as the need arises.

The poppet top 14 has one or more support arms 19, as shown in Figures 4a-4c.

The support arms 19 preferably extend outward laterally to provide support for the poppet

11 in relation to the chamber 4 wall. The support arms 19, in conjunction with the fins 16

on the lower flange portion 12, allow the poppet 11 to slide substantially longitudinally

along the axis of the housing body 1. The support arms 19 also brace the poppet against

lateral pressure that may be applied to the poppet top 14 as the valve is adjusted. At least

four support arms 19 are preferably provided, or any number of arms needed to provide

sufficient support in substantially all directions within the cylindrical wall of the chamber

4. The spaces 26 between the support arms 19 must also provide a sufficient flow area,

i.e., greater than the flow area of the orifice 5, so that this portion of the chamber does not

control the flow rate of the valve. This is also true with respect to all of the components of

the valve collectively positioned within the chamber 4. While the support arms 19 are

extended far enough to the chamber wall to provide lateral support, they preferably extend

to slightly inside the chamber wall to reduce friction between the arms 19 and the inside of

the chamber. The poppet top 14, with support arms 19, retains the upper end 28 of the

spring 25, either directly, as shown in Figures 2 and 3, or in conjunction with a retaining

ring, or spacer, applied between the spring and poppet top 14.

Preferably located on the poppet top 14 is the poppet's angled engagement surface

17. The engagement surface 17 is provided along substantially the same incline as the cam's engagement surface 39, located on adjustment cam 37 shown in Figures 5a-5c. The

location of the engagement surface 17 between two support arms 19 on the poppet top 14

makes it possible for the cam's engagement surface 39 to slide relative to the poppet's

engagement surface 17, while fitting between two of the support arms and, at the same

time, limiting the rotation of the engagement surfaces 17 and 39 in relation to one another.

The width 20 between the two support arms 19 is preferably only slightly wider than the

width of the cam's engagement surface 39, so that the relative rotation of the surfaces 17

and 39, and the poppet 11 and cam 37, respectively, to which they are connected, is

substantially restricted. The rotation of the poppet 11 in relation to cam 37 is limited so

that the engagement surfaces 17 and 39 will remain parallel to one another and slide in a

unidirectional manner during adjustments, thereby allowing adjustments to be precisely

made. It should be readily apparent that similar support guides can be placed on cam 37

and other portions of the valve to limit the relative rotation between the poppet 11 and cam

37, and that other means for limiting the rotation of the poppet, such as guides along the

chamber or orifice, can also be used.

Extending through the bore 10 located on the body 1, as shown in Figures 2 and 3,

is the threaded member 31. The threaded member 31, as shown in Figures 6a-6b, is

preferably a shaft or bolt with external threads 33 along at least a portion of its length. The

shaft has a head 35 at one end 34 and terminates at the other end 36. When inserted into

the body 1, the terminating end 36 is inserted into the notch 29 on the side of the chamber

4 opposite the bore 10 such that the threaded portion 33 of the shaft extends laterally

through the chamber 4 with the member 31 supported by the body 1. The head 35 is

positioned such that it can be accessed through the bore 10 from the exterior of the body. The head 35 is preferably an alien head, but can be a screw head, hex head, or other type

of head, to enable the threaded member 31 to be turned or rotated within the chamber 4.

Positioned on the threaded member 31, as shown in Figure 3, is the cam 37. The

cam 37, as shown in Figures 5a-5c, has a threaded bore 41 adapted for rotational

movement relative to the threaded portion 33 of the member 31. Turning the threaded

member 31 causes the cam 37 to move longitudinally thereon and, as shown in Figure 3,

laterally in relation to the chamber 4. The cam's engagement surface 39 extends from the

securing portion, and is oriented and adapted to engage and slide parallel with the poppet's

engagement surface 17 along substantially the same inclined plane 60, shown in Figure 3.

The angle of the two surfaces 17 and 39 and the inclined plane 60 is preferably about 45

degrees, although any angle which provides for relative movement of the two surfaces in

directions normal to each other is possible. When the threaded member 31 is turned and

the cam 37 is moved laterally, the two engagement surfaces slide relative to one another,

and, with the spring 25 urging the poppet 11 toward the cam 37, the sliding of the two

engagement surfaces 17 and 39 causes the poppet's engagement surface 17 and poppet 11

to move in a longitudinal direction, either toward or away from the orifice 5. Since the

cam retains the movement of the poppet upward, adjusting the cam 37 in this manner sets

the maximum travel distance of the poppet in relation to the orifice 5.

Both the poppet 11, including the poppet top 14, and cam 37, can be made of

virtually any strong, resilient material, but is preferably made of a composite such as

Delrin™ made by Dupont. The material preferably withstands extreme changes in

temperature and humidity and results in the two engagement surfaces 17 and 39 wearing

evenly and sliding relatively easily with low friction in relation to one another. The

material is also preferably light weight so that the movement of the poppet 11 is only nominally affected by the orientation of the valve. The poppet 11 and member 31 can be

formed by any conventional method, such as by injection molding.

A sealing cap 45 is provided, as shown in Figure 7a, to seal the bore 10. It

preferably has external threads 46 to match internal threads on the bore 10, such that the

cap 45 can be inserted within the bore and secured thereto to provide an airtight seal. The

cap 45 is adapted with a cavity 47 adjacent to which the head 35 can be positioned wherein

the cap helps secure the threaded member 31 within the chamber, preventing the member

31 from sliding while allowing it to rotate therein. In the preferred embodiment, an access

bore 49 is provided through the cap 45 so that the head 35 of the threaded member 31 can

be turned externally, i.e., from outside the body 1. A bushing 50, shown in Figure 9, is

preferably provided within the cavity 47 of the cap 45 to prevent leakage of fluid or gas

from the chamber 4 through the access bore 49.

The access bore 49 preferably has internal threads so that a separate break away

screw 51 can be inserted therein to prevent unauthorized adjustments of the threaded

member 31. The pitch on the threads 52, 53 on the screw 51 and access bore 49,

respectively, is preferably customized so that no standard screw can be inserted. The

break away screw 51 has a separate head 55, such as a screw head, alien head, hex head,

etc., which is adapted to be turned by any conventional means. The head 55 is supported

by a thin stem 56 which can be broken off after the valve is set and the screw 51 inserted.

Spacers 57, 59 and 61, as shown in Figures 8a and 8b, can be provided to widen

the range of threshold flow rates. The spacers are preferably annular in shape to match the

shape of the spring, although it should be apparent that spacers in virtually any shape can

be provided. One or more spacers can be inserted into the chamber adjacent the spring,

either on the upper end 28, or lower end 30, or both. The spacers help to adjust the threshold flow rate by compressing the spring and adjusting its tension for any given travel

distance of the poppet. Exemplary manners in which the spacers are inserted into the

chamber relative to the spring are shown in Figures 10, 11 and 13. The spacers 57, 59 and

61 can come in various widths depending on the desired Threshold Rate ranges. Any

number of spacers can be provided if desired.

In another embodiment of the present invention, as shown in Figures 9-14, the

system can be a multi-phase excess flow valve system. The structure and operation of this

valve system is similar to the valve system of the first embodiment, except that it has a

wider range of Threshold Rates. As substantially shown in Figures 9-14, a three-phase

housing design 70 is shown to demonstrate the multi-phase excess flow valve system. With

the three-phase housing design, three axially-displaced positions 63, 64 and 65, are provided

for the threaded member 31. The physical dimensions of other components of the valve

system may be adjusted to accommodate for insertion of the threaded member 31 in one of

the new positions. For each of the positions, the same coiled spring 25 with a pre-calibrated

tension, or different springs, if desired, can be used to cover a wide range of Threshold

Rates. Each position comprises a bore 10 and associated notch 29, as shown in Figures 9-

14, similar to those used in the first embodiment. Each position 63, 64 and 65 is located at a

predetermined distance from the orifice 5 to enable the range of threshold flow rates to be

expanded. The unused positions may be sealed using threaded plugs 67, as shown in Figure

7b, to prevent any leak or escape of the fluid or gas from the housing body 1. In

conjunction with the fine adjustments that can be made by the adjustment mechanism, the

multiple phase design valve system can be used to achieve virtually any desired range of

Threshold Rates. Although three positions are illustrated herein, it will be appreciated that 2, 4, 5 or more positions can similarly be provided, depending on the range of desired flow

rates and the fineness of the adjustment that is required.

In its open position, the valve system regulates the flow of the fluid or gas from an

area on one end 2 to another area at the opposite end 3. To adjust the valve, by rotating the

threaded member 31 with the head 35, the cam 37 can be laterally displaced in a direction

transverse to the flow direction or to the longitudinal axis of the valve body 1. The cam's

engagement surface 39, as discussed, is designed to slide in relation to the poppet's

engagement surface 17 along the inclined plane 60. In the embodiment shown in Figures 2

and 3, the lateral displacement of the cam 37 along member 31 away from the sealing cap

45, allows the poppet 11 to move up in response to the pressure of the spring 25, thereby

increasing the distance between the poppet seat 15 and orifice 5. Consequently, the

differential pressure created across the orifice 5 is decreased, thereby increasing the

Threshold Rate at which the valve system will shut down the flow of fluid or gas. On the

other hand, the displacement of cam 37 towards the sealing cap 45 causes the poppet 11 to

move down, thereby decreasing the distance between the poppet seat 15 and orifice 5.

Consequently, the differential pressure created across the orifice 5 is increased, thereby

decreasing the Threshold Rate. (Of course, the ramping structure of the inclined plane 60

could also be reversed, so that movement towards the sealing cap 45 would increase rather

than decrease the Threshold Rate). With this unique design, the valve system can be set to virtually any Threshold Rate.

In practice, the valve system may be used to regulate the flow of gas into a house

from an outside gas source. The maximum gas consumption rate (the rate at which all gas-

consuming equipment are turned on) for the house is first determined. Then, the Threshold

Rate is set to a desired level, e.g., about 10% higher than the maximum consumption rate. This is preferably done by a professional using a flowmeter. Hence, if the maximum

consumption rate is determined to be 100,000 BTUs (British Thermal Units), then the

Threshold Rate is set at around 110,000 BTUs by adjusting a pre-calibrated threaded

member 31. If the flow rate exceeds the set Threshold Rate, the poppet moves against the

spring 25 and toward the orifice 5, such that the poppet seat 15 presses against the receiving

portion 8, causing the valve system to shut down the supply of gas into the house, thereby

avoiding a potential catastrophic event. Using the design of the present invention, the valve

system can be set to any Threshold Rate with virtually an infinite degree of adjustability.

Figure 2 shows a cross-sectional view of an exemplary configuration of the excess

flow valve system used in its open position and Figure 3 shows the same valve from a

direction normal to the cross-section of Figure 2 in its closed position. As it slides up or

down, the poppet 11 is guided by the two or more guiding fins 16 and/or support arms 19.

The support arms 19 on the poppet top 14 ensure that the poppet slides longitudinally inside

the housing body 1 during its up and down motion. The support arms 19 also help to

stabilize the poppet during adjustments. Also, because too much lateral pressure on the

poppet top 14 can cause the support arms 19 to bind with the chamber 4 wall, when setting

the valve care should be taken to release the poppet by reversing the threaded member 31

slightly before the final setting is made. The poppet 11 is urged against the cam 37, as

shown in Figure 2, which retains the poppet's upward movement within the chamber 4, and,

when the Threshold Rate is exceeded, the poppet 11 quickly slides away from the cam 37

and toward the orifice 5, such that the poppet seat 15 seals the valve, as shown in Figure 3.

With respect to Figures 9-14, the present valve system can be employed to

significantly widen the range of potential threshold flow rates. For example, in one

embodiment that has been tested and developed, the range of threshold flow rates for natural gas can be extended from between about 30,000 BTU's to about 1.5 million BTU's. The

following shows the possible ranges that can be achieved with a single valve housing body,

using various size spacers, poppets and multiple-phase settings. In each of these samples, a

single spring with a pre-calibrated tension is used, with a three-phase housing body 1, along

with an adjustment mechanism with the engagement surfaces at 45 degrees. In each case,

precise adjustments that are substantially infinitely variable within the operating ranges can

be made without having to replace the spring, change the size of the orifice, or the like.

Assembly No. 1 : The assembly shown in Figure 9 employs a standard size poppet

11 with the threaded member 31 in the upper position 63. The operating range using the

adjustment mechanism of the present invention for this assembly is about 31,000 to 593,000

BTU's for natural gas, and about 47,000 to 944,000 BTU's for liquid petroleum.

Assembly No. 2: The assembly shown in Figure 10 employs a standard size poppet

11 with one spacer 61 (having .300 inch width) and threaded member 31 in the upper

position 63. The operating range using the adjustment mechanism of the present invention

for this assembly is about 39,000 to 916,000 BTU's for natural gas, and about 61,000 to

1,457,000 BTU's for liquid petroleum.

Assembly No. 3: The assembly shown in Figure 11 employs a standard size poppet

11 with two spacers 59 and 61 (having .200 and .300 inch widths, respectively) and

threaded member 31 in the upper position 63. The operating range using the adjustment

mechanism of the present invention for this assembly is about 52,000 to 793,000 BTU's for

natural gas, and about 82,000 to 1,262,000 BTU's for liquid petroleum.

Assembly No. 4: The assembly shown in Figure 12 employs a shorter poppet 69

with threaded member 31 in the middle position 64. The operating range using the adjustment mechanism of the present invention for this assembly is about 75,000 to 980,000

BTU's for natural gas, and about 119,000 to 1,561,000 BTU's for liquid petroleum.

Assembly No. 5: The assembly shown in Figure 13 employs a shorter poppet 69

with one spacer 57 (having .100 inch width) and threaded member 31 in the middle position

64. The operating range using the adjustment mechanism of the present invention for this

assembly is about 36,000 to 877,000 BTU's for natural gas, and about 57,000 to 1,395,000

BTU's for liquid petroleum.

Assembly No. 6: The assembly shown in Figure 14 employs a shorter poppet 69

with threaded member 31 in the bottom position 65. The operating range using the

adjustment mechanism of the present invention for this assembly is about 54,000 to 851,000

BTU's for natural gas, and about 86,000 to 1,354,000 BTU's for liquid petroleum.

With the valve system assemblies described above, the range of Threshold Rates is

likely to be sufficient for most applications where natural gas or liquid petroleum gas is

used. Accordingly, a single valve system where the settings can be adjusted on-site within a

wide range, without having to change the size of the housing body 1, the size of the orifice

5, or the tension on the spring 25, can be applied in a variety of applications where the fluid

or gas supply pressures vary. The settings are also capable of being reset and repeated

because the engagement surfaces typically wear evenly. And, where other applications

might require a different range of Threshold Rates, it should be understood that the above

threshold ranges can be varied further by changing the position of the threaded member 31 ,

the length of the poppet 11, and/or the size and number of the spacers. The range of motion

of the adjustment mechanism can also be adjusted, if desired.

Rather than having to replace the spring or change the orifice size to adjust the

Threshold Rate as in standard valves, one or more of the adjustment steps discussed above can be employed. For example, using a single valve housing body, one or more spacers can

be added to adjust the effective tension of the spring for any given setting to change the

range of possible Threshold Rates. The multiple-phase settings can also be used to widen

the range of Threshold Rates that are possible for any given size of housing body.

Moreover, the poppet itself can be changed to adjust the travel distance of the poppet and

therefore the Threshold Rate. The valve is then set using the adjustment mechanism to the

precise Threshold Rate by turning the threaded member 31 to a predetermined position, i.e.,

to a specific BTU level.

Tests have also been conducted using flowmeters that show the sensitivity of the

adjustment mechanism settings. For example, a pipe system with about 54 feet of ³A inch

pipe with an inlet supplying air, simulating natural gas, under constant pressure at one end

and a drill cap at the other end was tested. The system was designed to simulate conditions

where low pressure exists at the far end of the system away from the inlet. With the valve

Threshold Rate set at approximately 64,000 BTU's for natural gas (or 50 SCFH), the valve

that was tested shut down when a hole with a diameter of .1250 inches was drilled in the

drill cap. And, when the Threshold Rate was set at approximately 128,000 BTU's for

natural gas (or 100 SCFH), the valve shut down when a hole with a diameter of .1719

inches was drilled in the drill cap. Because the pressure in the system is higher at the inlet

end than at the far end, when a hole is drilled closer to the inlet end, such as within about 10

feet, the valve typically shuts off when the hole is smaller, i.e., half the size as the one

drilled at the far end. With the ability to set the valve to precise Threshold Rates, the

present valve is able to detect small as well as large leaks without confusing small leaks

with pilot light outages, or large leaks with all of the appliances being turned on, i.e.,

maximum consumption. While the present invention has been described in detail above, it should be

understood that it is not limited to the specific embodiments shown and described herein.

The present invention contemplates that embodiments not specifically described or shown

are within its scope, and that its scope is defined only by the claims that follow.

Claims (31)

What is claimed is:

1. A valve, comprising:

an outer housing having a chamber extending in a longitudinal direction, said

housing having an orifice located at one end of said chamber;

a poppet within said chamber movable in said longitudinal direction between an

open and closed position, said poppet being adapted to seal said orifice in said closed

position;

a spring member for urging said poppet in said longitudinal direction away from said

orifice to said open position;

an externally adjustable threaded member extending through said housing and into

said chamber;

a retainer for restricting the movement of said poppet in relation to said orifice in

said longitudinal direction, said retainer being associated with said threaded member such

that turning said threaded member causes a first angled surface on said retainer to move

longitudinally relative to said threaded member and laterally relative to said chamber;

a second angled surface located on said poppet which is urged by said spring

member substantially toward said first angled surface, wherein said first and second angled

surfaces are adapted to engage one another and slide with respect to one another along

substantially the same plane; and

wherein by externally turning the threaded member, the retainer can be moved

longitudinally in relation to said threaded member, and laterally in relation to said chamber,

and the location of said first angled surface can be adjusted and set to a predetermined

position, wherein the position of said first angled surface determines the maximum travel distance of said poppet in said longitudinal direction, whereby said position of said first

angled surface helps determine the threshold flow rate of said valve.

2. The valve of Claim 1, wherein the valve is adapted so that the rotation of the poppet

in relation to the retainer is substantially limited by one or more guides, wherein the first

and second angled surfaces are adapted to engage one another and slide relative to one

another substantially unidirectionally.

3. The valve of Claim 1, wherein the spring member substantially urges said second

angled surface against said first angled surface such that they are in substantial contact with

each other, wherein turning the threaded member causes the first angled surface to move

laterally relative to said second angled surface, moving said poppet either toward or away

from said orifice.

4. The valve of Claim 1, wherein the threaded member is substantially fixed in relation

to said housing in all directions except rotationally, wherein at least a portion of the

threaded member is substantially located within said chamber, said threaded member having

a head which can be accessed from the exterior of said housing, such that the threaded

member can be externally adjusted.

5. The valve of Claim 4, wherein a break-away plug is provided to prevent the head of

said threaded member from being turned once the threaded member is set.

6. The valve of Claim 1, wherein the poppet is provided with one or more support arms

to help support the poppet laterally within said chamber, said support arms being adapted to

allow the poppet to move freely in said longitudinal direction within said chamber.

7. The valve of Claim 1, wherein one or more spacers are provided within said

chamber to adjust the tension of said spring member and change the threshold flow rate of

said valve, wherein said one or more spacers are used to adjust the distance the spring member must be compressed to move the poppet to the closed position for any given

maximum travel distance of said poppet.

8. The valve of Claim 1, wherein said housing is provided with multiple settings on

which the threaded member can be positioned, wherein each of said settings is located on

said housing at a predetermined distance from said orifice, wherein by changing and

positioning said threaded member on a particular setting, the range of the threshold flow

rates can be adjusted.

9. The valve of Claim 8, wherein each of said multiple settings comprises an opening

on one side of the housing and a notch on the other side, wherein the threaded member can

be inserted through said opening and extended across the chamber into said notch on the

other side, wherein the threaded member is held within said housing in all directions except

rotationally, and is oriented laterally within said chamber.

10. The valve of Claim 1, wherein the retainer is substantially infinitely variable

between minimum and maximum settings on said threaded member, wherein the position of

said first angled surface can be accurately controlled by said threaded member, wherein the

sensitivity needed for low pressure applications is achieved by said valve.

11. A valve comprising:

a body having a chamber and an orifice located at one end of said chamber;

a poppet within said chamber movable between an open and closed position and

adapted to seal said orifice;

a spring member for urging said poppet away from said orifice to said open position;

and

an adjustment mechanism comprising an externally adjustable member and cam

movably associated therewith, wherein said cam moves in relation to said externally adjustable member and can be used to set the maximum travel distance of said poppet in

relation to said orifice, wherein the position of said cam on said member determines the

threshold flow rate of said valve.

12. The valve of Claim 11, wherein said externally adjustable member is threaded and

extends laterally within said chamber, wherein said cam is threadably associated with said

externally adjustable member such that by turning said member, said cam is moved

longitudinally along said member and laterally within said chamber.

13. The valve of Claim 12, wherein the cam has thereon a first angled surface which is

adapted to engage a second angled surface on said poppet, said second angled surface being

urged toward said first angled surface by said spring member, wherein moving said cam

longitudinally along said member in one direction causes said first and second angled

surfaces to slide in relation to one another, and said second angled surface to move in a

second direction, wherein the poppet is moved either toward or away from said orifice.

14. The valve of Claim 13, wherein the cam and/or poppet is adapted with one or more

guides such that the rotation of said poppet in relation to said cam is substantially restricted,

such that when said externally adjustable member is turned, and the cam is moved

longitudinally along said member, said first and second angled surfaces slide in relation to

one another along substantially the same plane and substantially unidirectionally.

15. The valve of Claim 11, wherein said exteranally adjustable member is substantially

fixed within said chamber except in the rotational direction, wherein turning the member

causes said cam associated therewith to move longitudinally in relation to said member and

laterally in relation to said chamber.

16. A method for adjusting the threshold flow rate of a gas or fluid flow system

containing natural gas, liquid petroleum, or the like, under pressure, comprising: providing a valve located downstream from the point where said gas is introduced

into said system, said valve comprising a body having a chamber and an orifice located at

one end of said chamber, a poppet within said chamber movable between an open and

closed position, and adapted to seal said orifice, a spring member for urging said poppet

away from said orifice to said open position, and an externally adjustable device which can

be used to set the maximum travel distance of said poppet in relation to said orifice, wherein

the position of said externally adjustable device is substantially infinitely variable between

first and second settings; and

setting said externally adjustable device between said first and second settings,

wherein the rotation of said poppet in relation to said externally adjustable device is

substantially limited.

17. The method of Claim 16, wherein the method comprises the additional step of

providing multiple settings on said body to adjust the location where said externally

adjustable member is connected to said body, wherein said multiple settings can change the

range between which the threshold flow rates can be adjusted.

18. The method of Claim 16, wherein the method comprises the additional step of

providing one or more spacers within said chamber to adjust the tension of said spring

member for any given maximum travel distance of said poppet, wherein said one or more

spacers are used to adjust the amount the spring member is compressed to move the poppet

to the closed position, thereby changing the threshold flow rate of said valve.

19. The method of Claim 16, wherein the method comprises the additional step of

providing poppets having different lengths, wherein a poppet having a predetermined length

is selected and used to change the range between which the threshold flow rates can be

adjusted.

20. The method of Claim 16, wherein prior to the step of setting said externally

adjustable device, the method comprises the additional steps of substantially expanding the

range of possible threshold flow rates by the following steps:

locating said externally adjustable device on one of multiple settings

provided on said body, wherein each of said multiple settings can be used to adjust

the location where said externally adjustable device is connected to said body;

providing one or more spacers within said chamber to adjust the tension of

said spring member for any given maximum travel distance of said poppet, wherein

said one or more spacers can be used to adjust the amount the spring member is

compressed to move the poppet to the closed position; and

selecting and using a predetermined poppet length.

AMENDED CLAIMS

[received by the International Bureau on the 16 September 1998 ( 16.09.98) ; original c laims 16-20 amended ; new c l aims 21 -31 added ; remain ing claims unchanged (4pages ) ] installing a valve with a poppet and orifice on said fluid flow system, said valve having an adjustment mechanism comprising an externally adjustable member and a cam movably associated therewith; determining the threshold flow rate of said fluid flow system;

setting the threshold flow rate of said valve by adjusting said externally adjustable member and moving said cam in relation thereto, wherein the position of said cam in relation to said externally adjustable member determines the maximum travel distance of said poppet in relation to said orifice.

17. The method of Claim 16, wherein the step of installing a valve on said fluid flow system comprises the additional step of providing a first angled surface on said cam and a second angled surface on said poppet, wherein said first and second angled surfaces engage one another to determine the maximum travel distance of said poppet in relation to said

orifice.

18. The method of Claim 17, wherein the method comprises the additional step of

limiting the rotational movement of said poppet in relation to said cam, wherein the rotational orientation of said first angled surface in relation to said second angled surface is maintained substantially constant.

19. The method of Claim 17, wherein the step of setting the maximum travel distance of said poppet in relation to said orifice comprises turning said externally adjustable member and causing said cam to move longitudinally thereon in a first direction, wherein moving said cam in said first direction causes said first and second angled surfaces to slide in relation to one another, and said poppet, which is urged toward said cam by a spring, to move in a second direction, either toward or away from said orifice.

20. The method of Claim 19, wherein the step of setting the threshold flow rate enables the valve to close when the threshold flow rate in said system is exceeded, wherein said threshold flow rate is exceeded when the pressure differential between the upstream and

downstream portions of said system is great enough to cause said poppet to overcome the pressure of said spring urging said poppet toward said cam and cause said poppet to slide toward and against said orifice.

21. The method of Claim 16, wherein the step of determining the threshold flow rate of said fluid flow system comprises the step of determining the maximum consumption rate of

said fluid flow system and adding a predetermined amount to said maximum consumption

rate.

22. The method of Claim 21, wherein said predetermined amount that is added to said maximum consumption rate is about 10 percent of the maximum consumption rate.

23. The method of Claim 16, wherein the method comprises the additional step of providing a plurality of settings on said valve and positioning said externally adjustable member on one of said settings, wherein the range of possible threshold flow rates can be adjusted thereby.

24. The method of Claim 16, wherein the method comprises the additional step of providing a spring that urges said poppet away from said orifice to an open position, and of providing one or more spacers which can, for any given maximum travel distance of said poppet, be used to adjust the tension of said spring, wherein said one or more spacers can be used to adjust the amount the spring must be compressed to cause the poppet to be moved to a closed position.

25. The method of Claim 16, wherein the method comprises the additional step of selecting a poppet having a predetermined length, wherein the length of said poppet can be used to adjust the range of possible threshold flow rates that can be employed by said method.

26. A valve, comprising: a body having a chamber and an orifice; a poppet within said chamber movable between an open and closed position, said poppet being adapted to seal said orifice in said closed position and having a first sliding surface thereon;

a spring for urging said poppet away from said orifice to said open position; an adjustment mechanism comprising an externally adjustable member and a second sliding surface extending therefrom, wherein said first and second sliding surfaces are adapted to engage one another to set the maximum travel distance of said poppet in relation to said orifice, wherein the position of said second sliding surface in relation to said first sliding surface determines the threshold flow rate of said valve; and a guide for limiting the rotation of said poppet in relation to said adjustment mechanism such that the rotational orientation of said first sliding surface in relation to said second sliding surface can be maintained substantially constant.

27. The valve of Claim 26, wherein when said first and second sliding surfaces are engaged with one another, said sliding surfaces extend along substantially the same angled plane.

28. The valve of Claim 26, wherein said guide is comprised of two or more guide surfaces extending on either side of said first and/or second sliding surfaces, wherein the distance between said two or more guide surfaces is only slightly greater than the width of said first and/or second sliding surfaces, such that the guide surfaces limit the extent to which said first sliding surface and said second sliding surface can rotate with respect to_. one another.

29. The valve of Claim 28, wherein by limiting the relative rotational movement of said first and second sliding surfaces, said first and second sliding surfaces are maintained substantially parallel to one another and slide relative to one another substantially uni- directionally along substantially the same plane during adjustments.

30. The valve of Claim 26, wherein support arms are extended from said poppet outward toward the chamber wall to stabilize said poppet during adjustments and to help support said poppet during longitudinal movement of said poppet in said chamber.

31. The valve of Claim 26, wherein said externally adjustable member comprises a threaded shaft that extends into said chamber, wherein a cam having a threaded bore associated with said threaded shaft is provided thereon, and wherein said second sliding surface is located on said cam such that by turning said externally adjustable member, said cam is moved longitudinally along said threaded shaft and causes said second sliding surface

to move in one direction, such that said second sliding surface slides in relation to said first sliding surface and causes said first sliding surface to move in a second direction.