GB2552350A - A metal-to-metal seal - Google Patents
A metal-to-metal seal Download PDFInfo
- Publication number
- GB2552350A GB2552350A GB1612564.3A GB201612564A GB2552350A GB 2552350 A GB2552350 A GB 2552350A GB 201612564 A GB201612564 A GB 201612564A GB 2552350 A GB2552350 A GB 2552350A
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- GB
- United Kingdom
- Prior art keywords
- metal
- seal member
- seal
- sealing edge
- metallic
- Prior art date
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Classifications
-
- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62C—FIRE-FIGHTING
- A62C37/00—Control of fire-fighting equipment
- A62C37/08—Control of fire-fighting equipment comprising an outlet device containing a sensor, or itself being the sensor, i.e. self-contained sprinklers
- A62C37/10—Releasing means, e.g. electrically released
- A62C37/11—Releasing means, e.g. electrically released heat-sensitive
- A62C37/14—Releasing means, e.g. electrically released heat-sensitive with frangible vessels
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- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62C—FIRE-FIGHTING
- A62C35/00—Permanently-installed equipment
- A62C35/58—Pipe-line systems
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/02—Sealings between relatively-stationary surfaces
- F16J15/06—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces
- F16J15/062—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces characterised by the geometry of the seat
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/02—Sealings between relatively-stationary surfaces
- F16J15/06—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces
- F16J15/08—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with exclusively metal packing
- F16J15/0806—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with exclusively metal packing characterised by material or surface treatment
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/02—Sealings between relatively-stationary surfaces
- F16J15/06—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces
- F16J15/08—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with exclusively metal packing
- F16J15/0887—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with exclusively metal packing the sealing effect being obtained by elastic deformation of the packing
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Health & Medical Sciences (AREA)
- Public Health (AREA)
- Business, Economics & Management (AREA)
- Emergency Management (AREA)
- Physics & Mathematics (AREA)
- Geometry (AREA)
- Gasket Seals (AREA)
Abstract
A method of manufacturing a metal-to-metal seal is provided. The method comprises the steps of: forming a burrless, metallic sealing edge 14 on a metallic first seal member 10; and arranging the sealing edge 14 of the first seal member 10 to be in contact with a metallic surface 18 of a metallic second seal member 12 so as to form the metal-to-metal seal. There is also provided a metal-to-metal seal. The metal-to-metal seal comprises metallic first and second seal members 10, 12, the first seal member 10 having a burrless, metallic sealing edge 14 formed thereon. The sealing edge 14 of the first seal member 10 is arranged to be in contact with a metallic surface 18 of the second seal member 12 so as to form the metal-to-metal seal.
Description
(71) Applicant(s):
Dualmist Fire Products Limited Barclays Bank Chambers, Market Street, HEBDEN BRIDGE, West Yorkshire, HX7 6AD, United Kingdom (72) Inventor(s):
Paul Cobb
| (51) INT CL: | |
| F16J 15/08 (2006.01) F16J 15/06 (2006.01) | A62C 35/58 (2006.01) |
| (56) Documents Cited: GB 2453843 A WO 2004/080539 A2 JPH08189585 | WO 2014/159766 A2 US 20030011143 A1 |
| (58) Field of Search: INT CLA62C, F16J Other: WPI; EPODOC |
(74) Agent and/or Address for Service:
Potter Clarkson LLP
The Belgrave Centre, Talbot Street, NOTTINGHAM, NG1 5GG, United Kingdom (54) Title of the Invention: A metal-to-metal seal
Abstract Title: A metal-to-metal seal and a method of manufacturing such a seal (57) A method of manufacturing a metal-to-metal seal is provided. The method comprises the steps of: forming a burrless, metallic sealing edge 14 on a metallic first seal member 10; and arranging the sealing edge 14 of the first seal member 10 to be in contact with a metallic surface 18 of a metallic second seal member 12 so as to form the metal-to-metal seal. There is also provided a metal-to-metal seal. The metal-to-metal seal comprises metallic first and second seal members 10, 12, the first seal member 10 having a burrless, metallic sealing edge 14 formed thereon. The sealing edge 14 of the first seal member 10 is arranged to be in contact with a metallic surface 18 of the second seal member 12 so as to form the metal-to-metal seal.
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A METAL-TO-METAL SEAL
This invention relates to a method of manufacturing a metal-to-metal seal, to a metal-tometal seal, to a method of manufacturing a fire sprinkler unit, and to a fire sprinkler unit.
It is known to use a seal to prevent leakage in a fluidic system, such as a fire sprinkler system.
According to a first aspect ofthe invention, there is provided a method of manufacturing a metal-to-metal seal, the method comprising the steps of:
• forming a burrless, metallic sealing edge on a metallic first seal member; and • arranging the sealing edge of the first seal member to be in contact with a metallic surface of a metallic second seal member so as to form the metal-to-metal seal.
For the purposes of this specification, an edge is defined as a line segment where two faces meet.
The formation of a metal-to-metal seal through contact between a burrless, metallic sealing edge and a metallic surface results in a metal-to-metal seal with excellent sealing capability. This is because the use of a burrless sealing edge enables the sealing edge to have the requisite sharpness to readily deform under relatively low pressures in order to form a sealing interface between the sealing edge and the metallic surface. The inventor has found that the sealing interface formed in this manner provides excellent sealing under relatively low pressures, even when the metallic surface has a less than desirable surface roughness, e.g. due to surface imperfections.
In addition the inventor has found that the metal-to-metal seal manufactured in accordance with the invention has an improved sealing capability when compared to other types of sealing techniques, such as the use of overlapping polished surfaces and the use of polymer seals. This is not only because of the aforementioned capability of the metal-tometal seal ofthe invention to provide excellent sealing under relatively low pressures and with a metallic surface with a less than desirable surface roughness, but also because the metal-to-metal seal of the invention is less likely to jam over a long period of time and can be released using a relatively low pressure (e.g. less than 0.1 bar) in comparison to other types of seals, such as rubber seals.
In embodiments of the invention, the first seal member may be made from a metallic material that is selected so that the sealing edge undergoes elastic deformation under compression when in contact with the metallic surface. This provides a reliable way of forming the sealing interface between the sealing edge and the metallic surface.
In further embodiments of the invention, the sealing edge and metallic surface may form the metal-to-metal seal under a load in the range of about 30kg to about 40 kg. It will be appreciated that the range of about 30kg to about 40 kg includes 30 kg and 40 kg.
In still further embodiments of the invention, the step of forming the burrless, metallic sealing edge on the metallic first seal member may include machining the first seal member to form the burrless, metallic sealing edge.
In embodiments of the invention employing the use of machining, the sealing edge may be formed by machining the first seal member along a first path and then machining the first seal member along a second path that transverses the first path, the sealing edge being defined by the intersection at which the first and second paths cross each other.
The above machining step therefore provides a reliable way of improving the sharpness of the sealing edge, which is beneficial in providing the metal-to-metal seal with excellent sealing capability. In contrast, machining the first seal member along a single continuous path around the sealing edge results in a sealing edge with reduced sharpness, which in turn reduces the sealing capability of the resultant metal-to-metal seal.
In embodiments of the invention employing the use of machining, the step of machining the metallic first seal member to form the burrless, metallic sealing edge may include pushing material away from the sealing edge.
Pushing material away from the sealing edge provides a reliable way of preventing burr formation at or near the sealing edge, which improves the sharpness of the sealing edge and thereby provides the metal-to-metal seal with excellent sealing capability.
The method of the invention may include a combination of the above machining steps. For example, machining the first seal member along the first path may include pushing material away from the intersection along the first path, and machining the first seal member along the second path may include pushing material away from the intersection along the second path.
In the method, the first seal member may include a seal member portion that is shaped to provide the first seal member with a spring characteristic.
The first seal member having a spring characteristic enables the metal-to-metal seal formed between the sealing edge and metallic surface to remain intact under circumstances in which an applied force has a tendency to separate the first seal member from the second seal member. For example, when the first seal member is mechanically coupled with another component, the spring characteristic of the first seal member allows the metal-to-metal seal to remain intact during a variation in temperature that results in the thermal expansion and contraction of the other component, because the spring characteristic of the first seal member is able to compensate for the thermal expansion and contraction of the other component.
Otherwise, in the absence of the spring characteristic in the first seal member, there is a risk that such thermal expansion and contraction of the other component could result in the first seal member being separated from the second seal member to thereby release the metal-to-metal seal, particularly when the first seal member and the other component have different thermal expansion coefficients.
In embodiments of the invention, the first seal member may include a frusto-conical or substantially frusto-conical seal member portion, and the sealing edge may define a circumference of the frusto-conical or substantially frusto-conical seal member portion.
The inclusion of a frusto-conical or substantially frusto-conical seal member portion in the first seal member enables the seal member portion to act as a spring member that provides the first seal member with a spring characteristic, which is similar to the spring characteristic exhibited by a Belleville washer. Such a spring characteristic improves the sealing capability of the metal-to-metal seal formed between the sealing edge and metallic surface.
In further embodiments of the invention, the sealing edge may have an edge radius in the range of about 0.05 mm to about 0.1 mm. It will be appreciated that the range of about 0.05 mm to about 0.1 mm includes 0.05 mm and 0.1 mm. Such an edge radius makes it straightforward to provide the sealing edge with the requisite sharpness to allow the sealing edge to undergo deformation under a relatively low compressive load.
It will be appreciated that the edge radius of the sealing edge may vary from the aforementioned range depending on sealing requirements of the metal-to-metal seal.
Each seal member is preferably made of a metallic material that provides the metal-tometal seal with desired properties.
Each seal member may be corrosion-resistant (e.g. acid corrosion-resistant). This allows the metal-to-metal seal to retain its sealing capability over a long period of time even when used in fluidic systems with corrosive fluids.
The first seal member may be made of phosphor bronze or stainless steel. Such metallic materials possess high elasticity to provide spring-like characteristics, are able to deform fractionally at the sealing edge under pressure, and are sufficiently strong to withstand loads of at least 30 kg. Phosphor bronze in particular is more stable, durable and longlasting than rubber, and hence the use of phosphor bronze to manufacture the metal-tometal seal of the invention results in a seal with improved sealing capability when compared to a rubber seal.
The second seal member may be made of brass.
In still further embodiments of the invention, the method may further include the steps of:
• after forming the sealing edge on the first seal member, storing the first seal member in a liquid bath;
• removing the first seal member from the liquid bath prior to forming the metal-tometal seal.
The purpose of storing the first seal member in the liquid bath is to minimise handling of the first seal member prior to forming the metal-to-metal seal in order to prevent accidental damage to the sealing edge that could adversely affect the sharpness of the sealing edge.
In such embodiments, the step of storing the first seal member in a liquid bath may include using air to eject the first seal member into the liquid bath. The use of air ejection to move the first seal member into the liquid path provides a reliable way of minimising handling of the first seal member when storing the first seal member in the liquid bath.
According to a second aspect of the invention, there is provided a metal-to-metal seal obtained using the method according to any one of the embodiments of the first aspect of the invention.
The features and advantages of the method of the first aspect of the invention and its embodiments apply mutatis mutandis to the metal-to-metal seal of the second aspect of the invention and its embodiments.
According to a third aspect of the invention, there is provided a metal-to-metal seal comprising metallic first and second seal members, the first seal member having a burrless, metallic sealing edge formed thereon, the sealing edge of the first seal member arranged to be in contact with a metallic surface of the second seal member so as to form the metal-to-metal seal.
The features and advantages of the method of the first aspect of the invention and its embodiments apply mutatis mutandis to the metal-to-metal seal of the third aspect of the invention and its embodiments.
In the metai-to-metal seal, the first seal member may be made from a metallic material that is selected so that the sealing edge undergoes elastic deformation under compression when in contact with the metallic surface.
In the metal-to-metal seal, the sealing edge and metallic surface may form the metal-tometal seal under a load in the range of about 30 kg to about 40 kg. It will be appreciated that the range of about 30kg to about 40 kg includes 30 kg and 40 kg.
In the metal-to-metal seal, the first seal member may include a seal member portion that is shaped to provide the first seal member with a spring characteristic.
In the metal-to-metal seal, the first seal member may include a frusto-conical or substantially frusto-conical seal member portion, and the sealing edge defines a circumference of the frusto-conical or substantially frusto-conical seal member portion.
In the metal-to-metal seal, the sealing edge has an edge radius in the range of about 0.05 mm to about 0.1 mm. It will be appreciated that the range of about 0.05 mm to about 0.1 mm includes 0.05 mm and 0.1 mm.
In the metal-to-metal seal, each seal member may be corrosion-resistant (e.g. acid corrosion-resistant).
In the metal-to-metal seal, the first seal member may be made of phosphor bronze or stainless steel, and/or the second seal member may be made of brass.
According to a fourth aspect of the invention, there is provided a method of manufacturing a fire sprinkler unit, the method including the steps of:
• providing a metal-to-metal seal, wherein the metal-to-metal seal is in accordance with any one ofthe embodiments ofthe second and third aspects ofthe invention;
• arranging the metal-to-metal seal within a housing of the fire sprinkler unit.
In a preferred embodiment of the invention, the housing may include an internal channel through which fluid may flow, a first end ofthe internal channel may be connectable to an external fluid source, the second seal member may be formed at a second end of the internal channel, and the housing may further include at least one orifice connecting the interior and exterior of the housing. In such embodiments, the method may further include the steps of:
• providing an activation element;
• configuring the activation element to hold the first seal member against the second seal member so that the sealing edge of the first seal member is arranged to be in contact with the metallic surface of the second seal member so as to form the metal-to-metal seal to prevent any fluid inside the internal channel from flowing to the or each orifice; and • configuring the activation element to be activatable to separate the first seal member from the second seal member in order to release the metal-to-metal seal.
In the method of the invention, the activation element may be a heat-sensitive activation element (such as a frangible thermo bulb) that is configured to be activatable at a predetermined temperature to separate the first seal member from the second seal member in order to release the metal-to-metal seal.
According to a fifth aspect ofthe invention, there is provided a fire sprinkler unit comprising a housing and a metal-to-metal seal, wherein the metal-to-metal seal is in accordance with any one of the embodiments of the second and third aspects of the invention, wherein the metal-to-metal seal is arranged within the housing.
In a preferred embodiment of the invention, the housing may include an internal channel through which fluid may flow, a first end of the internal channel may be connectable to an external fluid source, the second seal member may be formed at a second end of the internal channel, and the housing may further include at least one orifice connecting the interior and exterior of the housing, in such embodiments, the fire sprinkler unit may further include an activation element that is configured to hold the first seal member against the second seal member so that the sealing edge of the first seal member is arranged to be in contact with the metallic surface of the second seal member so as to form the metal-tometal seal to prevent any fluid inside the internal channel from flowing to the or each orifice, and wherein the activation element may be configured to be activatable to separate the first seal member from the second seal member in order to release the metal-to-metal seal.
In the fire sprinkler unit of the invention, the activation element may be a heat-sensitive activation element (such as a frangible thermo bulb) that is configured to be activatable at a predetermined temperature to separate the first seal member from the second seal member in order to release the metal-to-metal seal
The features and advantages of the method of the first aspect of the invention, the metalto-metal seal of the second and third aspects of the invention and their embodiments apply mutatis mutandis to the method of the fourth aspect of the invention, the fire sprinkler unit of the fifth aspect of the invention and their embodiments.
The provision of the metal-to-metal seal in the housing of the fire sprinkler unit of the invention provides improved sealing of a fluidic pathway in the fire sprinkler unit housing under relatively low pressures when compared to conventional sealing techniques, examples of which are described above. As mentioned above, the use of a burrless sealing edge enables the sealing edge to have the requisite sharpness to readily deform under relatively low pressures in order to form a sealing interface between the sealing edge and the metallic surface, and the sealing interface formed in this manner provides excellent sealing under relatively low pressures, even when the metallic surface has a less than desirable surface roughness. Thus, such a sealing interface between the sealing edge and the metallic surface is readily and reliably formed under relatively low pressures that are present in the fluidic pathway in the fire sprinkler unit housing prior to the activation of the fire sprinkler unit to dispense fluid.
Moreover, the use of the metal-to-metal seal to provide sealing in the fire sprinkler unit reduces the number of components in the fire sprinkler unit when compared to the use of polymer seals to provide the required sealing.
Furthermore, when the first seal member has a spring characteristic, the metal-to-metal seal formed between the sealing edge and metallic surface remains intact during a variation in temperature that results in the thermal expansion and contraction of the activation element. Otherwise, in the absence of the spring characteristic in the first seal member, such thermal expansion and contraction of the activation element may result in separation of the first seal member from the second seal member, which in turn results in accidental release of the metal-to-metal seal before the activation element is activated.
Preferred embodiments of the invention will now be described, by way of non-limiting examples, with reference to the accompanying drawings in which:
Figure 1 shows schematically a metal-to-metal seal according to an embodiment of the invention;
Figure 2 shows schematically an isometric perspective view of the first seal member of the metal-to-metal seal of Figure 1;
Figure 3 shows schematically a bottom view of the first seal member of the metalto-metal seal of Figure 1;
Figure 4 shows schematically a cross-section of the first seal member along lines A-A shown in Figure 3;
Figure 5 shows schematically a magnified view of a sealing edge formed on the first seal member of Figure 4;
Figures 6 and 7 show schematically a fire sprinkler unit according to a further embodiment of the invention; and
Figure 8 shows schematically a cross-section of the fire sprinkler unit along lines A-A shown in Figure 7.
The figures are not necessarily to scale, and certain features and certain views of the figures may be shown exaggerated in scale or in schematic form in the interests of clarity and conciseness.
A metal-to-metal seal according to an embodiment of the invention is shown in Figures 1 to 4.
The metal-to-metal seal comprises first and second seal members 10, 12.
The first seal member 10 has a burrless, metallic sealing edge 14 formed thereon, as shown in Figure 4. More particularly, the first seal member 10 includes a frusto-conical seal member portion 16, with the sealing edge 14 defining a circumference of the frustoconical seal member portion 16. The sealing edge 14 has a preferred edge radius in the range of 0.05 mm to 0.1 mm, which enables the sealing edge 14 to readily undergo deformation under a relatively low compressive load.
The sealing edge 14 of the first seal member 10 is arranged to be in contact with a metallic surface 18 of the second seal member 12 so that the sealing edge 14 undergoes elastic deformation under compression when in contact with the metallic surface 18 in order to form the metal-to-metal seal.
The use of a burrless sealing edge 14 enables the sealing edge 14 to have the requisite sharpness to readily deform under relatively low pressures in order to form a sealing interface between the sealing edge 14 and the metallic surface 18. As mentioned earlier in this specification, the sealing interface formed in this manner provides excellent sealing under relatively low pressures, even when the metallic surface 18 has a less than desirable surface roughness. In addition the metal-to-metal seal is less likely to jam over a long period of time and can be released using a relatively low pressure (e.g. less than 0.1 bar) in comparison to other types of seals, such as rubber seals.
The inclusion of the frusto-conical seal member portion 16 in the first seal member 10 enables the seal member portion 16 to act as a spring member that provides the first seal member 10 with a spring characteristic that improves the sealing capability of the metalto-metal seal formed between the sealing edge 14 and metallic surface 18. It will be appreciated that the angle of each face, which defines the sealing edge 14, relative to the metallic surface 18 of the second seal member 12 may be increased in order to increase the sharpness of the sealing edge 14 and thereby aid the deformation of the sealing edge 14 to form the sealing interface with the metallic surface 18 of the second seal member 12.
The first seal member 10 is preferably made of phosphor bronze (e.g. phosphor bronze PB101) or stainless steel (e.g. stainless steel 303). The second seal member 12 is preferably made of brass.
The use of such materials enables the seal members 10, 12 to be corrosion-resistant, which beneficially allows the metal-to-metal seal to retain its sealing capability over a long period of time even when used in fluidic systems with corrosive fluids (including potentially acidic water in fire sprinkler units).
The aforementioned materials also possess high elasticity to provide spring-like characteristics, are able to deform fractionally at the sealing edge 14 under pressure, and are sufficiently strong to withstand loads of at least 30 kg. This allows the sealing edge 14 to readily undergo elastic deformation under compression when in contact with the metallic surface 18 in order to reliably form the sealing interface between the sealing edge 14 and the metallic surface 18.
Phosphor bronze in particular is more stable, durable and long-lasting than rubber, and hence the use of phosphor bronze to manufacture the metal-to-metal seal results in a seal with improved sealing capability when compared to a rubber seal.
The formation of a metal-to-metal seal through contact between a burrless, metallic sealing edge 14 and a metallic surface 18 as set out above therefore results in a metal-to-metal seal with excellent sealing capability.
Tests under British Standard 8458 have been carried out on the metal-to-metal seal. The first test is heat aging for 3 months in a hot bath, and the second test is a water hammer test in which water pressure is increased from zero bar to 30 bar 2000 times. The metalto-metal seal has been found to retain its sealing capability, i.e. it does not leak, after undergoing each test.
The metal-to-metal seal may be manufacturing in accordance with the following manufacturing steps.
The first seal member 10 is initially machined to form the burrless, metallic sealing edge 14 on the first seal member 10.
The machining is carried out using a cermet insert tool, with a 0.2 mm radius, which is configured to carry out both internal (boring) and external (turning) machining. The feed rate is 0.03 mm/rev and the spindle speed is 3000 rpm, but it will be appreciated that these values are not critical, and other feed rates and spindle speeds may be used.
The sealing edge 14 is formed by machining the first seal member 10 along a first path 20 and then machining the first seal member 10 along a second path 22 that transverses the first path 20, the sealing edge 14 being defined by the intersection at which the first and second paths 20, 22 cross each other, as shown in Figure 5. The machining of the seal members 10, 12 involves pushing material away from the intersection along the first path 20, and then pushing material away from the intersection along the second path 22.
The above machining steps permits the formation of a sealing edge 14 without any burr formation, since any burrs would be pushed away from the intersection that defines the sealing edge 14, and thereby provides a sealing edge 14 with the desired edge radius and sharpness in order to obtain an excellent sealing capability.
After the sealing edge 14 is formed on the first seal member 10, the first seal member 10 is then ejected using air to move the first seal member 10 into a water bath for temporary storage. Thereafter, the first seal member 10 is removed from the water bath (e.g. using tweezers), while taking care to avoid contact with the sealing edge 14, and then is degreased.
The sealing edge 14 of the first seal member 10 is then arranged to be in contact with a metallic surface 18 of the second seal member 12 so as to form the metal-to-metal seal shown in Figure 1.
The metal-to-metal seal may be used in a fire sprinkler unit. More specifically, the metalto-metal seal may be arranged within a housing of a fire sprinkler unit.
Figures 6 and 7 show schematically a fire sprinkler unit 26 according to a further embodiment of the invention. Figure 8 shows schematically a cross-section of the fire sprinkler unit 26 along lines A-A shown in Figure 7.
The fire sprinkler unit 26 comprises a housing with an internal channel 28 through which water may flow. A first end of the internal channel 28 is connected, in use, to an external water source 30 to permit introduction of water into the internal channel 28. The second seal member 12 is formed at a second end of the internal channel 28. The housing further includes a plurality of circumferentially arranged orifices 32 that connects the interior and exterior of the housing.
The first seal member 10 is mechanically coupled to a frangible thermo bulb 34 (which is typically made of glass) such that the thermo bulb 34 supports the first seal member 10 to hold it against the second seal member 12 in order to enable the sealing edge 14 and metallic surface 18 to form the metal-to-metal seal. Formation of the metal-to-metal seal in this manner prevents the water inside the internal channel 28 from flowing to the orifices and thereby prevents the fire sprinkler unit 26 from discharging water via the orifices.
In the embodiment shown, the thermo bulb 34 and first seal member 10 are arranged such that the sealing edge 14 and metallic surface 18 form the metal-to-metal seal under a load in the range of about 30 kg to about 40 kg, which is several times lower than the breaking strength of the thermo bulb 34.
The thermo bulb 34 is configured to break at a predetermined temperature, which is typically an elevated temperature relative to ambient temperature. When the thermo bulb 34 breaks, the thermo bulb 34 is no longer capable of holding the first seal member 10 against the second seal member 12, thus allowing the water pressure in the internal channel 28 to push the first seal member 10 away from the second seal member 12 in order to release the metal-to-metal seal. This in turn allows water inside the internal channel 28 to flow to the orifices 32 in order to enable the fire sprinkler unit 26 to discharge water via the orifices 32.
In use, a variation in temperature may result in thermal expansion and contraction of the thermo bulb 34.
Normally the different thermal expansion coefficients of the first seal member 10 and the thermo bulb 34 means that thermal expansion and contraction of the thermo bulb 34 could result in the first seal member 10 being separated from the second seal member 12, which in turn results in accidental release of the metal-to-metal seal before the thermo bulb 34 breaks.
Such accidental release of the metal-to-metal seal before the thermo bulb 34 breaks is avoided through the provision of a spring characteristic in the first seal member 10, which enables the metal-to-metal seal formed between the sealing edge 14 and metallic surface 18 to remain intact during the aforementioned variation in temperature that results in the thermal expansion and contraction of the thermo bulb 34. This is because the spring characteristic of the first seal member 10 is able to compensate for the thermal expansion and contraction of the thermo bulb 34.
It will be appreciated that the thermo bulb 34 may be replaced by a different activation element that is configured to:
hold the first seal member 10 against the second seal member 12 so that the 5 sealing edge 14 of the first seal member 10 is arranged to be in contact with the metallic surface 18 of the second seal member 12 so as to form the metal-to-metal seal to prevent any fluid inside the internal channel 28 from flowing to the orifices 32, and be activatable to separate the first seal member 10 from the second seal member in order to release the metal-to-metal seat.
It will also be appreciated that the numerical values specified in this specification are selected to illustrate the working principle of the invention or to illustrate preferred embodiments of the invention, and the specified numerical values may be replaced by other numerical values within the scope of the invention.
Claims (33)
1. A method of manufacturing a metal-to-metal seal, the method comprising the steps of:
• forming a burrless, metallic sealing edge on a metallic first seal member; and • arranging the sealing edge of the first seal member to be in contact with a metallic surface of a metallic second seal member so as to form the metal-to-metal seal.
2. A method according to Claim 1 wherein the first seal member is made from a metallic material that is selected so that the sealing edge undergoes elastic deformation under compression when in contact with the metallic surface.
3. A method according to Claim 1 or Claim 2 wherein the sealing edge and metallic surface form the metal-to-metal seal under a load in the range of about 30 kg to about 40 kg.
4. A method according to any one of the preceding claims wherein the step of forming the burrless, metallic sealing edge on the metallic first seal member includes machining the first seal member to form the burrless, metallic sealing edge.
5. A method according to Claim 4 wherein the sealing edge is formed by machining the first seal member along a first path and then machining the first seal member along a second path that transverses the first path, the sealing edge being defined by the intersection at which the first and second paths cross each other.
6. A method according to Claim 4 or Claim 5 wherein the step of machining the metallic first seal member to form the burrless, metallic sealing edge includes pushing material away from the sealing edge.
7. A method according to Claims 5 and 6 wherein machining the first seal member along the first path includes pushing material away from the intersection along the first path, and machining the first seal member along the second path includes pushing material away from the intersection along the second path.
8. A method according to any one of the preceding claims wherein the first seal member includes a seal member portion that is shaped to provide the first seal member with a spring characteristic.
9. A method according to any one of the preceding claims wherein the first seal member includes a frusto-conical or substantially frusto-conical seal member portion, and the sealing edge defines a circumference of the frusto-conical or substantially frustoconical seal member portion.
10. A method according to any one of the preceding claims wherein the sealing edge has an edge radius in the range of about 0.05 mm to about 0.1 mm.
11. A method according to any one of the preceding claims wherein each seal member is corrosion-resistant.
12. A method according to any one of the preceding claims wherein the first seal member is made of phosphor bronze or stainless steel, and/or the second seal member is made of brass.
13. A method according to any one of the preceding claims further including the steps of:
• after forming the sealing edge on the first seal member, storing the first seal member in a liquid bath;
• removing the first seal member from the liquid bath prior to forming the metal-tometal seal.
14. A method according to Claim 13 wherein the step of storing the first seal member in a liquid bath includes using air to eject the first seal member into the liquid bath.
15. A metal-to-metal seal obtained using the method according to any one of the preceding claims.
16. A metal-to-metal seal comprising metallic first and second seal members, the first seal member having a burrless, metallic sealing edge formed thereon, the sealing edge of the first seal member arranged to be in contact with a metallic surface of the second seal member so as to form the metal-to-metal seal.
17. A metal-to-metal seal according to Claim 16 wherein the first seal member is made from a metallic material that is selected so that the sealing edge undergoes elastic deformation under compression when in contact with the metallic surface.
18. A metal-to-metal seal according to Claim 16 or Claim 17 wherein the sealing edge and metallic surface form the metal-to-metal seal under a load in the range of about 30 kg to about 40 kg.
19. A metal-to-metal seal according to any one of Claims 16 to 18 wherein the first seal member includes a seal member portion that is shaped to provide the first seal member with a spring characteristic.
20. A metal-to-metal seal according to any one of Claims 16 to 19 wherein the first seal member includes a frusto-conical or substantially frusto-conical seal member portion, and the sealing edge defines a circumference of the frusto-conical or substantially frustoconical seal member portion.
21. A metal-to-metal seal according to any one of Claims 16 to 20 wherein the sealing edge has an edge radius in the range of about 0.05 mm to about 0.1 mm.
22. A metal-to-metal seal according to any one of Claims 16 to 21 wherein each seal member is corrosion-resistant.
23. A metal-to-metal seal according to any one of Claims 16 to 22 wherein the first seal member is made of phosphor bronze or stainless steel, and/or the second seal member is made of brass.
24. A method of manufacturing a fire sprinkler unit, the method including the steps of:
• providing a metal-to-metal seal, wherein the metal-to-metal seal is in accordance with any one of Claims 15 to 23;
• arranging the metal-to-metal seal within a housing of the fire sprinkler unit.
25. A method of manufacturing a fire sprinkler unit according to Claim 24, wherein the housing includes an internal channel through which fluid may flow, a first end of the internal channel connectable to an external fluid source, the second seal member formed at a second end of the internal channel, the housing further including at least one orifice connecting the interior and exterior of the housing, the method further including the steps of:
providing an activation element;
• configuring the activation element to hold the first seal member against the second seal member so that the sealing edge of the first seal member is arranged to be in contact with the metallic surface of the second seal member so as to form the metal-to-metal seal to prevent any fluid inside the internal channel from flowing to the or each orifice; and • configuring the activation element to be activatable to separate the first seal member from the second seal member in order to release the metal-to-metal seal.
26. A method according to Claim 25 wherein the activation element is a heat-sensitive activation element that is configured to be activatable at a predetermined temperature to separate the first seal member from the second seal member in order to release the metalto-metal seal.
27. A fire sprinkler unit comprising a housing and a metal-to-metal seal, wherein the metal-to-metal seal is in accordance with any one of Claims 15 to 23, wherein the metalto-metal seal is arranged within the housing.
28. A fire sprinkler unit according to Claim 27 wherein the housing includes an internal channel through which fluid may flow, a first end of the internal channel connectable to an external fluid source, the second seal member formed at a second end of the internal channel, the housing further including at least one orifice connecting the interior and exterior ofthe housing, wherein the fire sprinkler unit further includes an activation element that is configured to hold the first seal member against the second seal member so that the sealing edge of the first seal member is arranged to be in contact with the metallic surface of the second seal member so as to form the metal-to-metal seal to prevent any fluid inside the internal channel from flowing to the or each orifice, and wherein the activation element is configured to be activatable to separate the first seal member from the second seal member in order to release the metal-to-metal seal.
29. A fire sprinkler unit according to Claim 28 wherein the activation element is a heatsensitive activation element that is configured to be activatable at a predetermined temperature to separate the first seal member from the second seal member in order to release the metal-to-metal seal.
30. A method of manufacturing a metal-to-metal seal substantially as herein described with reference to and/or as illustrated in the accompanying figures.
31. A metal-to-metal seal substantially as herein described with reference to and/or as illustrated in the accompanying figures.
5
32. A method of manufacturing a fire sprinkler unit substantially as herein described with reference to and/or as illustrated in the accompanying figures.
33. A fire sprinkler unit substantially as herein described with reference to and/or as illustrated in the accompanying figures.
Intellectual
Property
Office
Application No: GB1612564.3 Examiner: Mr Kevin Hewitt
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1612564.3A GB2552350A (en) | 2016-07-20 | 2016-07-20 | A metal-to-metal seal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1612564.3A GB2552350A (en) | 2016-07-20 | 2016-07-20 | A metal-to-metal seal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB201612564D0 GB201612564D0 (en) | 2016-08-31 |
| GB2552350A true GB2552350A (en) | 2018-01-24 |
Family
ID=56890645
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1612564.3A Withdrawn GB2552350A (en) | 2016-07-20 | 2016-07-20 | A metal-to-metal seal |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2552350A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08189585A (en) * | 1995-01-09 | 1996-07-23 | Hitachi Ltd | Vacuum flange |
| US20030011143A1 (en) * | 2001-07-11 | 2003-01-16 | Satsuo Shinoda | Metallic gasket for vacuum device and method of producing thereof |
| WO2004080539A2 (en) * | 2003-03-11 | 2004-09-23 | Tyco Fire Products Lp | An upright, early suppression fast response sprinkler |
| GB2453843A (en) * | 2007-10-17 | 2009-04-22 | Dril Quip Inc | A gasket designed to withstand pressure differentials in subsea environments |
| WO2014159766A2 (en) * | 2013-03-14 | 2014-10-02 | Tyco Fire Products Lp | Fire protection sprinkler trigger assembly |
-
2016
- 2016-07-20 GB GB1612564.3A patent/GB2552350A/en not_active Withdrawn
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08189585A (en) * | 1995-01-09 | 1996-07-23 | Hitachi Ltd | Vacuum flange |
| US20030011143A1 (en) * | 2001-07-11 | 2003-01-16 | Satsuo Shinoda | Metallic gasket for vacuum device and method of producing thereof |
| WO2004080539A2 (en) * | 2003-03-11 | 2004-09-23 | Tyco Fire Products Lp | An upright, early suppression fast response sprinkler |
| GB2453843A (en) * | 2007-10-17 | 2009-04-22 | Dril Quip Inc | A gasket designed to withstand pressure differentials in subsea environments |
| WO2014159766A2 (en) * | 2013-03-14 | 2014-10-02 | Tyco Fire Products Lp | Fire protection sprinkler trigger assembly |
Also Published As
| Publication number | Publication date |
|---|---|
| GB201612564D0 (en) | 2016-08-31 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |