CA1128030A - Firesafe fluid control valve - Google Patents
Firesafe fluid control valveInfo
- Publication number
- CA1128030A CA1128030A CA345,372A CA345372A CA1128030A CA 1128030 A CA1128030 A CA 1128030A CA 345372 A CA345372 A CA 345372A CA 1128030 A CA1128030 A CA 1128030A
- Authority
- CA
- Canada
- Prior art keywords
- ring
- metallic
- firesafe
- control valve
- fluid control
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- 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
- F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
- F16K5/00—Plug valves; Taps or cocks comprising only cut-off apparatus having at least one of the sealing faces shaped as a more or less complete surface of a solid of revolution, the opening and closing movement being predominantly rotary
- F16K5/06—Plug valves; Taps or cocks comprising only cut-off apparatus having at least one of the sealing faces shaped as a more or less complete surface of a solid of revolution, the opening and closing movement being predominantly rotary with plugs having spherical surfaces; Packings therefor
- F16K5/0663—Packings
- F16K5/0673—Composite packings
-
- 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
- F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
- F16K1/00—Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces
- F16K1/16—Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces with pivoted closure-members
- F16K1/18—Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces with pivoted closure-members with pivoted discs or flaps
- F16K1/22—Lift valves or globe valves, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces with pivoted closure-members with pivoted discs or flaps with axis of rotation crossing the valve member, e.g. butterfly valves
- F16K1/226—Shaping or arrangements of the sealing
- F16K1/2263—Shaping or arrangements of the sealing the sealing being arranged on the valve seat
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Taps Or Cocks (AREA)
- Details Of Valves (AREA)
- Lift Valve (AREA)
Abstract
ABSTRACT
"FIRESAFE FLUID CONTROL VALVE"
A valve member 17 when positioned so as to prevent fluid flow through a passage 11 in a valve body 10 engages a ring 14 made of flexible resilient fluorocarbon synthetic resin material, the ring 14 providing a fluid-tight seal between the valve member 17 and a seat 12 on the body 10. In the event of the ring 14 failing, the valve member 17 engages a back-up ring 15 made of a high temperature, non-metallic material which is non-galling, such as graphite. The high temperature properties of the ring 15 thus enable the valve to remain fluid-tight when shut even if the flexible ring 14 is destroyed by fire. The ring 15 can be compression-formed in situ into a shape which ensures close contact with the valve member 17. In the event of the ring 15 also failing, the valve member 17 comes into contact with a metallic ring 13 from which it is normally spaced and thereby restricts the flow of fluid through the valve.
This arrangement can be applied to butterfly-type valves (Figure 1) as well as to ball-type valves (Figure 4).
"FIRESAFE FLUID CONTROL VALVE"
A valve member 17 when positioned so as to prevent fluid flow through a passage 11 in a valve body 10 engages a ring 14 made of flexible resilient fluorocarbon synthetic resin material, the ring 14 providing a fluid-tight seal between the valve member 17 and a seat 12 on the body 10. In the event of the ring 14 failing, the valve member 17 engages a back-up ring 15 made of a high temperature, non-metallic material which is non-galling, such as graphite. The high temperature properties of the ring 15 thus enable the valve to remain fluid-tight when shut even if the flexible ring 14 is destroyed by fire. The ring 15 can be compression-formed in situ into a shape which ensures close contact with the valve member 17. In the event of the ring 15 also failing, the valve member 17 comes into contact with a metallic ring 13 from which it is normally spaced and thereby restricts the flow of fluid through the valve.
This arrangement can be applied to butterfly-type valves (Figure 1) as well as to ball-type valves (Figure 4).
Description
~Z8~130 ~ lis invention relates to a fluid control valve, particularly though not exclusively of the butterfly or ball type, which can be made firesafe.
Con~entional firesafe fluid control valves typically comprise a seat including a flexible ring with which a val~e member is engageable to prsvent fluid flow through the valve, the flexible ring being made of a soft material such as P.T.~.E. In the event of the flexible ring being destroyed by fire, the valve member is arranged to contact a metallic lip on the seat to maintain the valve shut.
However, in order to satisfy the relevant British Standard 5146, close contact must be ensured between the valve member and the metallic lip, which poses very large manufacturing problems. These problems become more acute in larger valves, since the permissible clearance between the valve member and the metallic lip becomes less as the size of the valve is increased. In addition, where the valve is of the butterfly or ball type wherein there is angular movement of the valve member relative to the seat, problems arisa due to "pick-up" or galling of the co-acting surfaces of the valve member and the metallic lip .
It is an object of the present invention to pro~ide a fluid control valve which is capable of satisfying the requirements of the aforementioned British Standard 5146, and which obviates or mitigates the above-described problems. In this connection, references to British Standard 5146 are intended to mean BS.5146:1974 both as originally drafted and as proposed to be amended at the date of filing of thisapplication.
According to the present invention, there is provided a fluid control ~alve comprising a body having a through passage, a valve member mo~able between a first position ,~
~Z~3~3(~
in which it permits fluid flow through the passage and a second position in which it prevcnt3 such fluid flow, a flexible ring which nor~ally pr~Yides a seal between the body and the valve member when in its second posi~ion, and a further ring of high temperature, non-metallic material which is arranged to pro~ide a seal between the body and the ~alve member in its second position in the e~ent of failure of the flexible ring so as to prevent fluid flow through the passage.
The non-metallic ring is preferably intended to be resistant to temperatures of at least 600 C. The material of the non-metallic ring can a~so be inherently non-galling:
for example, the non-metallic ring can be made of graphite.
Advantageously, a seat surrounds the passage in the body and incorporates a metallic mounting ring having a sùrface which is normally spaced from the valve member in its second position, but which is arranged to be engaged thereby in the e~ent of failure of both the flexible ring and the non-metallic ring so as to restrict the flow of fluid through said passage. The fle.~ible ring and/or the non-metallic ring are preferably incorporated into the seatJ
in which case the mounting ring advantageously ha~ an annular recess therein into which the non-metallic ring is compression-formed. In one particular arrangement, the mounting ring is composed of two annular parts which are axially engaged so as to retain the non-metallic ring therebetween: in this case, one of the annular parts can be interposed between the fle~ib~e ring and the non-metallic ring.
The flexible ring is preferably made of flexible resilient fluorocarbon synthetic resin material, such as P.T.~.E., and is preferably also subject to cold flow.
~Z~Q30 The valve may take the form of a butterfly valve in which the valve- member is a disk mo~n~2d on the body so as to be pivotable about an axis transverse to the a~is of the through passage. DastrabLy, the disk has a part-spherical peripheral surf`ace which engages the flexible ring when the valve member is in its-second position, and the pivot a~is is offset from both the plane of the dis~
and the axis of the through ?a~sage, for e~ample in the manner described in ~ritish Patent ~o. I290325. In Ihis case, the flexible ring is preferably of the type ~isclosed in British Patent No.1305554.
Alternatively, the valve may take the form of a ball valve in which the valve member is a ball mounted in the body so as to be rotatable about an axis transverse to the axis of the through passage, the ball having a through bore which communicates with the through passage in the body when the valve member i9 in its first position. In this case, two seats are advantageously provided respectively surrounding parts of the through paqsage on oppoqite sides of the ball, each seat incorporating a flexible rin~ and a high-temperature, non-metallic rin~.
Embodiments of the present invention will now be described, by way of e~a~ple, with ref`erence to the accompanying drawings, in which:-Figure 1 is a sectional side view of a fluid controlvalve according to the present invention, in the form of a butterfly valve;
Figure 2 is an enlarged view of part of the valve shown in ~igure 1, illustrating in particular a seat thereof;
~Z8(~30 Figure 3 is a similar view to ~lgure 2 of an alternative form of seat; and Figure 4 is a sectionai side view of a flui.d oon~rol.
valve according to the present invention, in the form o a ball valve.
Referring first to Figures 1 and 2, the butterfly valve shown therein comprises a body 10 having a through passage 11, and a seat 12 which is secured to one a.~ial end of the bocly 10 and which surrounds the passage 11. The seat 12 is composed of a metallic ring 13 ~hich supports two further rin~s 14 amd 15. The ring lJI is made of fle~ible resilient fluorocarbon synthetic resin mater;al (such as PoT~F~ ) wllich ls suhject to cold flo~, for a purpose which will be explained la-ter. In the particul2-embodiment illustrated, the flexible ring 1~ is Or the type described in British Patent ~o 1305554, I`he ring 15 is made of a high-temperature, non-metallic material which is non-galling; e.Yamples of such a material are "Gl~A~OIL" ~Re~istered Trade ~larlc)~ a form of graphi.te marketed by Union Carbide Corporation and "GRAh~`TITE", a form of graphite marketecl bv Crane Pac~in~ Ltd. The non-metallic ring 1; is receivecl in an annular resess 16 in the mounting ring 13 ~hictl has unclercut surfaces providing protection against the ring 15 bein~.r hlo~n o~lt by the pressure of the fluid flot~ing th.-ou~h the passage 'I 'I ~ the rin~ 15 being compression-formecl withi.n the recess 16.
A val~e member in the form of a disk 17 hav.ing a part-spherical peripheral surface 1~ ~s mountecl in t~e body 10 so as to be pivotabl- about an a~is 19 perpendicular to the a~is of the passage 11, the disk 17 being pivotable between a first position ¦shown in broken lines i~ Figure 1) in which it permits f`luid flow through the passage 11 and a second positior.
(shown in full lines in ~igure 1) in which l~Z8(~30 _ 6 --the surface 18 engages the flexible ring 14 so as ~o prevent such fluid flow. In its second position, the disk 17 is also in light contact with the non-metallic ring 15.
~he pivot a~is 1Q is sffset ~roln bo~h ~he piane of t;he disk 17 and the axis of the passa2e 11, and the centre of the part-spherical surface 18 ies on the a.~is of the passage 11 when the disk 17 is in its second position.
This arragement causes the surface 18 to lift away from the flexible ring 14 when the disk l7 is pivoted out of its second position, so that the valve does not rely on an interference fit between these parts to achieve fluid-tight closing, Because the fle~ible ring 14 is subject to cold flow, engagement thereof by the disl~ 17 effectively cold-forms the ring 14 to a reguired shape, sufficient resilience remaining to urge the co-acting surfaces of ~he ring 14 and the disk 17 into close contact. Such cold-forming of the ring 14 is assisted by its shape, and reference is directed to the aforementioned British Patent ~o. 130554 for a further explanation of this.
In the event of the fle.Yible ring 14 being destroyed by fire or otherwise failing, the disk 17 when in its second position will engage closely the non-metallic ring 15 so as effectively to prevent fluid flow through the passage 11; more particularly, the leaka~e rat~ of the non-metallic ring is sufficiently low to satisfy British Standard 5146, In the event that the non-me~allic rlng 15 also fails, for example due to mechanlcal damage, the disk 17 when in its second position will engage a surface 20 (see Figure 2) on the metallic mounting ring 13 which is normally spaced from the disk 1~, thereby restricting the flow of fluid through the passage 11.
In order to prevent the escape of fluid to atmosphere, an annular seal 20a is provided between the body 10 and the metallic ring 13 so as to surround the passage 11 The seal 20a is made of graphite or graphite-based rnaterial and is compression formed into a suitably shaped recess in ths metallic ring 13.
The valve described above is designed for fluid flow
Con~entional firesafe fluid control valves typically comprise a seat including a flexible ring with which a val~e member is engageable to prsvent fluid flow through the valve, the flexible ring being made of a soft material such as P.T.~.E. In the event of the flexible ring being destroyed by fire, the valve member is arranged to contact a metallic lip on the seat to maintain the valve shut.
However, in order to satisfy the relevant British Standard 5146, close contact must be ensured between the valve member and the metallic lip, which poses very large manufacturing problems. These problems become more acute in larger valves, since the permissible clearance between the valve member and the metallic lip becomes less as the size of the valve is increased. In addition, where the valve is of the butterfly or ball type wherein there is angular movement of the valve member relative to the seat, problems arisa due to "pick-up" or galling of the co-acting surfaces of the valve member and the metallic lip .
It is an object of the present invention to pro~ide a fluid control valve which is capable of satisfying the requirements of the aforementioned British Standard 5146, and which obviates or mitigates the above-described problems. In this connection, references to British Standard 5146 are intended to mean BS.5146:1974 both as originally drafted and as proposed to be amended at the date of filing of thisapplication.
According to the present invention, there is provided a fluid control ~alve comprising a body having a through passage, a valve member mo~able between a first position ,~
~Z~3~3(~
in which it permits fluid flow through the passage and a second position in which it prevcnt3 such fluid flow, a flexible ring which nor~ally pr~Yides a seal between the body and the valve member when in its second posi~ion, and a further ring of high temperature, non-metallic material which is arranged to pro~ide a seal between the body and the ~alve member in its second position in the e~ent of failure of the flexible ring so as to prevent fluid flow through the passage.
The non-metallic ring is preferably intended to be resistant to temperatures of at least 600 C. The material of the non-metallic ring can a~so be inherently non-galling:
for example, the non-metallic ring can be made of graphite.
Advantageously, a seat surrounds the passage in the body and incorporates a metallic mounting ring having a sùrface which is normally spaced from the valve member in its second position, but which is arranged to be engaged thereby in the e~ent of failure of both the flexible ring and the non-metallic ring so as to restrict the flow of fluid through said passage. The fle.~ible ring and/or the non-metallic ring are preferably incorporated into the seatJ
in which case the mounting ring advantageously ha~ an annular recess therein into which the non-metallic ring is compression-formed. In one particular arrangement, the mounting ring is composed of two annular parts which are axially engaged so as to retain the non-metallic ring therebetween: in this case, one of the annular parts can be interposed between the fle~ib~e ring and the non-metallic ring.
The flexible ring is preferably made of flexible resilient fluorocarbon synthetic resin material, such as P.T.~.E., and is preferably also subject to cold flow.
~Z~Q30 The valve may take the form of a butterfly valve in which the valve- member is a disk mo~n~2d on the body so as to be pivotable about an axis transverse to the a~is of the through passage. DastrabLy, the disk has a part-spherical peripheral surf`ace which engages the flexible ring when the valve member is in its-second position, and the pivot a~is is offset from both the plane of the dis~
and the axis of the through ?a~sage, for e~ample in the manner described in ~ritish Patent ~o. I290325. In Ihis case, the flexible ring is preferably of the type ~isclosed in British Patent No.1305554.
Alternatively, the valve may take the form of a ball valve in which the valve member is a ball mounted in the body so as to be rotatable about an axis transverse to the axis of the through passage, the ball having a through bore which communicates with the through passage in the body when the valve member i9 in its first position. In this case, two seats are advantageously provided respectively surrounding parts of the through paqsage on oppoqite sides of the ball, each seat incorporating a flexible rin~ and a high-temperature, non-metallic rin~.
Embodiments of the present invention will now be described, by way of e~a~ple, with ref`erence to the accompanying drawings, in which:-Figure 1 is a sectional side view of a fluid controlvalve according to the present invention, in the form of a butterfly valve;
Figure 2 is an enlarged view of part of the valve shown in ~igure 1, illustrating in particular a seat thereof;
~Z8(~30 Figure 3 is a similar view to ~lgure 2 of an alternative form of seat; and Figure 4 is a sectionai side view of a flui.d oon~rol.
valve according to the present invention, in the form o a ball valve.
Referring first to Figures 1 and 2, the butterfly valve shown therein comprises a body 10 having a through passage 11, and a seat 12 which is secured to one a.~ial end of the bocly 10 and which surrounds the passage 11. The seat 12 is composed of a metallic ring 13 ~hich supports two further rin~s 14 amd 15. The ring lJI is made of fle~ible resilient fluorocarbon synthetic resin mater;al (such as PoT~F~ ) wllich ls suhject to cold flo~, for a purpose which will be explained la-ter. In the particul2-embodiment illustrated, the flexible ring 1~ is Or the type described in British Patent ~o 1305554, I`he ring 15 is made of a high-temperature, non-metallic material which is non-galling; e.Yamples of such a material are "Gl~A~OIL" ~Re~istered Trade ~larlc)~ a form of graphi.te marketed by Union Carbide Corporation and "GRAh~`TITE", a form of graphite marketecl bv Crane Pac~in~ Ltd. The non-metallic ring 1; is receivecl in an annular resess 16 in the mounting ring 13 ~hictl has unclercut surfaces providing protection against the ring 15 bein~.r hlo~n o~lt by the pressure of the fluid flot~ing th.-ou~h the passage 'I 'I ~ the rin~ 15 being compression-formecl withi.n the recess 16.
A val~e member in the form of a disk 17 hav.ing a part-spherical peripheral surface 1~ ~s mountecl in t~e body 10 so as to be pivotabl- about an a~is 19 perpendicular to the a~is of the passage 11, the disk 17 being pivotable between a first position ¦shown in broken lines i~ Figure 1) in which it permits f`luid flow through the passage 11 and a second positior.
(shown in full lines in ~igure 1) in which l~Z8(~30 _ 6 --the surface 18 engages the flexible ring 14 so as ~o prevent such fluid flow. In its second position, the disk 17 is also in light contact with the non-metallic ring 15.
~he pivot a~is 1Q is sffset ~roln bo~h ~he piane of t;he disk 17 and the axis of the passa2e 11, and the centre of the part-spherical surface 18 ies on the a.~is of the passage 11 when the disk 17 is in its second position.
This arragement causes the surface 18 to lift away from the flexible ring 14 when the disk l7 is pivoted out of its second position, so that the valve does not rely on an interference fit between these parts to achieve fluid-tight closing, Because the fle~ible ring 14 is subject to cold flow, engagement thereof by the disl~ 17 effectively cold-forms the ring 14 to a reguired shape, sufficient resilience remaining to urge the co-acting surfaces of ~he ring 14 and the disk 17 into close contact. Such cold-forming of the ring 14 is assisted by its shape, and reference is directed to the aforementioned British Patent ~o. 130554 for a further explanation of this.
In the event of the fle.Yible ring 14 being destroyed by fire or otherwise failing, the disk 17 when in its second position will engage closely the non-metallic ring 15 so as effectively to prevent fluid flow through the passage 11; more particularly, the leaka~e rat~ of the non-metallic ring is sufficiently low to satisfy British Standard 5146, In the event that the non-me~allic rlng 15 also fails, for example due to mechanlcal damage, the disk 17 when in its second position will engage a surface 20 (see Figure 2) on the metallic mounting ring 13 which is normally spaced from the disk 1~, thereby restricting the flow of fluid through the passage 11.
In order to prevent the escape of fluid to atmosphere, an annular seal 20a is provided between the body 10 and the metallic ring 13 so as to surround the passage 11 The seal 20a is made of graphite or graphite-based rnaterial and is compression formed into a suitably shaped recess in ths metallic ring 13.
The valve described above is designed for fluid flow
2~3~3 therethrough only in the direction of arrow 21 in Figure 2, since fluid flow in the opposite direction would tend to dislodge the non-metallic ring 15 from the mounting ring 13 in the event that the flexiblc ring 14 fails. Figure 3 illustrates a modification of the valve in ~hich bi-direct-ional fluid flo~ is permitted. In this modification, the metallic mounting ring 13 is composed of two annular parts 22 and 23 which are axially engaged and which retain the non-metallic ring 15 therebetween, one of the annular parts 23 being interposed between the ring 15 and the flexible ring 14. The part 23 is also disposed between the part 22 and the body 10 so that the non-metallic ring lS is still retained between the parts 22 and 23 if the flexible ring 14 fails. The non-metallic rin2 15 is compression-formed in a recess 24 in the annular part 22 using a die whose configuration matches that of the annular part 23.
Referring now to Figure 4, the ball valve shown therein comprises a metallic body 30 formed from two parts 31 and 32 which are secured together by bolts 33. The body 30 has a through passage 34 formed therein which passes through a valve chamber 35 irl which a valve member in the form of a ball 36 having a through bore 37 is housed. The ball 36 can be rotat~d by mean~ of an operating member 38 about an axis 39 perpendicular to the a~is of the passage 34 between a first position in which the bore 37 communicates with the passage 34 so as to permi~ fluid ~lo~
through the valve (as indicated ir~ broken lines), and a second position in which the bore 37 doe~ not comlnunicate with the passage 34 ~as indicated in $~1 lines), thereby preventing fluld flow through the valve.
Two seats 40 are disposed in the valve chamber 35 and respectively surround parts of the passage 34 on opposite sides o~ the ball 36 Each seat 40 incorporates a r ng 41 made of` flexible resilient fluorocarbon synthetic resin material, such as P.T ~ E., which is sealingly engaged with the external surface of the ball 36, and a ring ! 2 made of a high-~emperature, non-galling, non-metallic - ~2~30 material which islighly contactadbv the ball 36. As in the ernbodiments of F`igures 1 to 3, each non-metallic ring 42 is made of graphite-based material. Fach ring 42 is received in a respective annular recess 43 in the body 30 which is so shaped as to protect the ring from blowing out under the pressure of the fluid flowing through the valve. Adjacent each recess 43, the body 30 is shaped so as to form an annular lip 44 which is spaced from the external surface of the ball 36, In the event of failure of the fle~ible ring 41 of either seat 40, the ball 36 will closely engage the respective non-metallic ring 42 thereby maintaining effect~ive fluid-tight closure of the valve. In the event of the non-metallic ring 41 failing also, the ball 36 w~ll engage the respective lip 44 so as to restrict the flow of fluid through the valve, In all of the above-described embodiments, the high temperature properties of the non-metallic rings 15,42 enable the valve to remain effectively fluid-tight when shut even if the fle.~ible rings 14,41 are destroyed by fire. Moreoever, since the non-metallic rings 15,42 can be compression-formed, it is comparatively simple to make them iIl a shape which will ensure close contact with ~he valve member so as to maintain fluid-tight closing of the valve, ~urthern1ore, even if the valve is subsequently damaged causing failure of the non-metallic rings 15,42 the mounting ring 13 in Figures 1 to 3 and the lips 44 in ~igure 4 still maintain the valve in a low leakage condition, Thus, the valves are able to satisfy the requirements of Bntish Standard 5146, Because the valve has a high temperature capability in a non-o.~idising environment, it is particularly suited for use in the field of petrochemicals,
Referring now to Figure 4, the ball valve shown therein comprises a metallic body 30 formed from two parts 31 and 32 which are secured together by bolts 33. The body 30 has a through passage 34 formed therein which passes through a valve chamber 35 irl which a valve member in the form of a ball 36 having a through bore 37 is housed. The ball 36 can be rotat~d by mean~ of an operating member 38 about an axis 39 perpendicular to the a~is of the passage 34 between a first position in which the bore 37 communicates with the passage 34 so as to permi~ fluid ~lo~
through the valve (as indicated ir~ broken lines), and a second position in which the bore 37 doe~ not comlnunicate with the passage 34 ~as indicated in $~1 lines), thereby preventing fluld flow through the valve.
Two seats 40 are disposed in the valve chamber 35 and respectively surround parts of the passage 34 on opposite sides o~ the ball 36 Each seat 40 incorporates a r ng 41 made of` flexible resilient fluorocarbon synthetic resin material, such as P.T ~ E., which is sealingly engaged with the external surface of the ball 36, and a ring ! 2 made of a high-~emperature, non-galling, non-metallic - ~2~30 material which islighly contactadbv the ball 36. As in the ernbodiments of F`igures 1 to 3, each non-metallic ring 42 is made of graphite-based material. Fach ring 42 is received in a respective annular recess 43 in the body 30 which is so shaped as to protect the ring from blowing out under the pressure of the fluid flowing through the valve. Adjacent each recess 43, the body 30 is shaped so as to form an annular lip 44 which is spaced from the external surface of the ball 36, In the event of failure of the fle~ible ring 41 of either seat 40, the ball 36 will closely engage the respective non-metallic ring 42 thereby maintaining effect~ive fluid-tight closure of the valve. In the event of the non-metallic ring 41 failing also, the ball 36 w~ll engage the respective lip 44 so as to restrict the flow of fluid through the valve, In all of the above-described embodiments, the high temperature properties of the non-metallic rings 15,42 enable the valve to remain effectively fluid-tight when shut even if the fle.~ible rings 14,41 are destroyed by fire. Moreoever, since the non-metallic rings 15,42 can be compression-formed, it is comparatively simple to make them iIl a shape which will ensure close contact with ~he valve member so as to maintain fluid-tight closing of the valve, ~urthern1ore, even if the valve is subsequently damaged causing failure of the non-metallic rings 15,42 the mounting ring 13 in Figures 1 to 3 and the lips 44 in ~igure 4 still maintain the valve in a low leakage condition, Thus, the valves are able to satisfy the requirements of Bntish Standard 5146, Because the valve has a high temperature capability in a non-o.~idising environment, it is particularly suited for use in the field of petrochemicals,
Claims (16)
PR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A firesafe fluid control valve comprising a body having a through passage, a valve member movable between a first position in which it permits fluid flow through the passage and a second position in which it prevents such fluid flow, a flexible ring which normally provides a seal between the body and the valve member when in its second position, a further ring of high-temperature non-metallic material which is arranged to provide a seal between the body and the valve member in the event of failure of the flexible ring, and a metallic seat having a surface which is normally spaced from the valve member when the latter is in its second position but which is arranged to be engaged by the valve member in the event of failure of the non-metallic ring also, the non-metallic ring being disposed between the flexible ring and said surface of the metallic seat.
2. A firesafe fluid control valve as claimed in Claim 1, wherein the non-metallic ring is resistant to temperature of at least 600°C.
3. A firesafe fluid control valve as claimed in Claim 1, wherein the material of the non-metallic ring is inherently non-galling.
4. A firesafe fluid control valve as claimed in Claim 1, wherein the non-metallic ring is made of graphite or graphite-based material.
5. A firesafe fluid control valve as claimed in Claim 1, wherein the flexible ring and/or the non-metallic ring are incorporated into the metallic seat.
6. A firesafe fluid control valve as claimed in Claim 5, wherein the metallic seat has an annular recess therein into which the non-metallic ring is compression-formed.
7. A firesafe fluid control valve as claimed in Claim 6, wherein the recess has undercut surfaces which serve to retain the non-metallic ring therein.
8. A firesafe fluid control valve as claimed in Claim 6, wherein the metallic seat is composed of two annular parts which are axially engaged so as to retain the non-metallic ring therebetween.
9. A firesafe fluid control valve as claimed in Claim 6, wherein a sealing gasket is provided between the metallic seat and the body, the sealing gasket being made of graphite or graphite-based material and being compression-formed in a recess in the metallic seat.
10. A firesafe fluid control valve as claimed in Claim 1, wherein the flexible ring is made of flexible resilient fluorocarbon synthetic resin material.
11. A firesafe fluid control valve as claimed in Claim 10, wherein the flexible ring is made of p.t.f.e.
12. A firesafe fluid control valve as claimed in Claim 10, wherein the flexible ring is also subject to cold flow.
13. A firesafe fluid control valve as claimed in Claim 1, wherein the valve member is a disk mounted on the body so as to be pivotable about an axis transverse to the axis of the through passage.
14. A firesafe fluid control valve as claimed in Claim 13, wherein the disk has a part-spherical peripheral surface which engages the flexible ring when the valve member is in its second position, and the pivot axis is offset from both the plane of the disk and the axis of the through passage.
15. A firesafe fluid control valve as claimed in Claim 1, wherein the valve member is a ball mounted in the body so as to be rotatable about an axis transverse to the axis of the through passage, the ball having a through bore which communicates with the through passage in the body when the valve member is in its first position.
16. A firesafe fluid control valve as claimed in Claim 15 wherein two metallic seats are provided respectively surrounding parts of the through passage on opposite sides of the ball, each seat incorporating a flexible ring and a high-temperature non-metallic ring.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7905588 | 1979-02-16 | ||
| GB7905588 | 1979-02-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1128030A true CA1128030A (en) | 1982-07-20 |
Family
ID=10503249
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA345,372A Expired CA1128030A (en) | 1979-02-16 | 1980-02-11 | Firesafe fluid control valve |
Country Status (6)
| Country | Link |
|---|---|
| AU (1) | AU531113B2 (en) |
| CA (1) | CA1128030A (en) |
| DE (1) | DE3005289A1 (en) |
| FR (1) | FR2453338A1 (en) |
| IT (1) | IT1148763B (en) |
| ZA (1) | ZA80723B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2942341A1 (en) * | 1979-10-19 | 1981-04-30 | Litton Industrial Products, Inc., Hartford, Conn. | Fire safe butterfly valve - has resilient high-temp. destructible seal and seat ring pre-loaded against valve |
| DE3336879A1 (en) * | 1983-10-11 | 1985-04-25 | Harald 6707 Schifferstadt Hoffmann | Valve-seating device, in particular for rotary cone servo-valves |
| US4649949A (en) * | 1986-03-05 | 1987-03-17 | Keystone International, Inc. | Fireproof valve assembly and seal element for use therein |
| DE3800705A1 (en) * | 1988-01-13 | 1989-08-10 | Jansen Gmbh Th | Sealing arrangement for shut-off flaps |
-
1980
- 1980-02-07 ZA ZA00800723A patent/ZA80723B/en unknown
- 1980-02-11 CA CA345,372A patent/CA1128030A/en not_active Expired
- 1980-02-13 DE DE19803005289 patent/DE3005289A1/en not_active Ceased
- 1980-02-15 AU AU55579/80A patent/AU531113B2/en not_active Ceased
- 1980-02-15 IT IT19960/80A patent/IT1148763B/en active
- 1980-02-15 FR FR8003752A patent/FR2453338A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| FR2453338B3 (en) | 1981-11-20 |
| DE3005289A1 (en) | 1980-09-04 |
| IT8019960A0 (en) | 1980-02-15 |
| AU531113B2 (en) | 1983-08-11 |
| IT1148763B (en) | 1986-12-03 |
| AU5557980A (en) | 1980-08-21 |
| ZA80723B (en) | 1981-02-25 |
| FR2453338A1 (en) | 1980-10-31 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |