CA2054610A1 - Valve for low pressure high temperature applications - Google Patents
Valve for low pressure high temperature applicationsInfo
- Publication number
- CA2054610A1 CA2054610A1 CA 2054610 CA2054610A CA2054610A1 CA 2054610 A1 CA2054610 A1 CA 2054610A1 CA 2054610 CA2054610 CA 2054610 CA 2054610 A CA2054610 A CA 2054610A CA 2054610 A1 CA2054610 A1 CA 2054610A1
- Authority
- CA
- Canada
- Prior art keywords
- disc
- axial extremity
- metallic seal
- flexible metallic
- valve
- 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.)
- Abandoned
Links
Landscapes
- Lift Valve (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A butterfly valve apparatus includes a valve body having an interior wall defining a generally cylindrical passageway having a centerline. A shaft having a centerline extends generally diametrically through the valve body. The shaft is carried by the valve body to permit rotation with respect to the body. A valve disc is mounted on the shaft in onset relationship fro n the centerline of the shaft. The disc is movable between an open position in which the disc is aligned with the centerline of the passageway and a closed position in which the disc is disposed in perpendicular relationship to the centerline of the passageway. A flexible metallic seal has a generally cylindrical for n and has first and second axial extremities. The first axial extremity is carried on the wall of the passageway in the housing. The disc engages the second axial extremity of the flexible metallic seal in the closed position. In many embodiments of the invention the periphery of the valve disc has clearance with respect to the passageway in the valve body.
A butterfly valve apparatus includes a valve body having an interior wall defining a generally cylindrical passageway having a centerline. A shaft having a centerline extends generally diametrically through the valve body. The shaft is carried by the valve body to permit rotation with respect to the body. A valve disc is mounted on the shaft in onset relationship fro n the centerline of the shaft. The disc is movable between an open position in which the disc is aligned with the centerline of the passageway and a closed position in which the disc is disposed in perpendicular relationship to the centerline of the passageway. A flexible metallic seal has a generally cylindrical for n and has first and second axial extremities. The first axial extremity is carried on the wall of the passageway in the housing. The disc engages the second axial extremity of the flexible metallic seal in the closed position. In many embodiments of the invention the periphery of the valve disc has clearance with respect to the passageway in the valve body.
Description
- ` 2 BACKGROUND OF THE INVENTION
The invention relates to valves and particularly to butter~y valves having particular application for the control of fluids at low pressure and high temperature. One such application is in exhaust systems of automobiles. For example, the valve in accordance with one form of the invention is used in an exhaust system for a diesel engine. More particularly, the system may utilize two such valves. Each valve is disposed in a pipe extending to one of t~,vo ~Iter systems. At any one instant one valve ;s open and the other is closed. Thus, one filter is operative to filter the exhaust gases and the other is heated to burn trapped contaminates inside the filter.
The prior art includes butterfly valves that have a metallic seat for use at high tempera-tures. One such valve is shown in United States patent 4,487,216 having the sameassignee as the present application. Typically, the metallic seal is generally annular and the valve is used to control a fluid at relatively high pressure. The design of such prior art valves tvpically has a wide ~ange and the valve uses a high pressure ~uid, in the order of 50 psi, to push the metallic seal against the periphery of the valve dis Other prior art diesel exhaust system valves have used a metal body in which the seat is machined. Typically the valve disc was thick and heavy. This relatively expensive construction was unsatisfactory because the valve allowed an excessive leakage be-tween the valve disc and the valve seat. An additional disadvantage was that the valve disc did not clean the valve seat when the valve was opened. Because the diesel exhaust 2 ~
contains substantial particulate matter, namely carbon black, the failure to clean the valve seat is particularly significant~ The accumulation of carbon black on the valve seat causes further increase in valve leakage.
Fhe body of prior art valves was considerably more massive than the closure member.
The closure member would expand faster than the valve body. The expansion of the valve body was restricted since, the outside temperature of the valve body was lower than the inside temperature of the valve body. Differences ben,veen the expansion of the valve body and the closure member caused the body and the closure member to seize together.
Prior art exhaust brake valves have been used with diesel engines. Such valves typically stopped the flow of exhaust gasses when the driver removed his foot from the ac-celerator pedal. The purpose of such valves was to slow the vehicle by causing increased engine braking. Such valves also had a high leak rate and did not clean the carbon deposits ~rom the valve seat when the valve opened.
The prior art flexible metallic seals have generally been secured to valvc housings by cl~nping arrangements that have lirnited radial movement of the seal and thus limited the precision with which the seal engaged the butterfly particularly where substantial pressures are not available to aid in urging the seal against the periphery of the buUerfly or valve disc~
2 ~
Stick or overlay welding techniques have been used to form a seat on a valve body. This technique forrns a weld bead on the valve body and that bead is machined to form thc valve seat~ This technique is relatively expensive. In addition, such arrangcmcnts arc subject to substantial leakage because of the inilexibility of the seat.
It is an object of the invention to provide a butterfly valve which will function to control a high temperature low pressure fluid. More particularly, it is an object of the invention to provide a valve that will function with fluids having a temperaturc rangc of -20 dcgrees Fahrcnheit to 1000 degrees Fahrenheit and a pressurc which is bctwcen approxirnately 1 and 5 psi.
Still another object of the in,vention is to provide a valve that will have a valve body and valve disc combination tbat~ill not result in inordinate expansion of one part, and thus degradation of valve operation, as hot ~uids initially pass through the valve.
It is an object of the present invention to provide a valvc which will automadcally clean the valve seat when thc valvc disc is opened~
It is yet another objca of thc invention to provide apparatus which is incxpcnsIve to manufacture~
It is still another object of the invention to provide apparatus which will utilize a sheet metal valve seat~
2 ~
SUMMARY OF THE INVENTION
It has now been found that these and other objects of the invention may be attained in a butterfly valve apparatus which includes a valve body hav~ng an interior wall defining a generally cylindrical passageway having a centerline. A shaft having a centerline extends generally diametrically through the valve body. The shaft is carried by the valve body to perrnit rotation with respect to the body. A valve disc is mounted on the shaft in offset relationship from the centerline of the shaft. The disc is movable between an open position in which the disc is aligned with the centerline of the passageway and a closed position in which the disc is disposed in perpendicular relationship to the centerline of the passageway. A flexible metallic seal has a generally cylindrical form and has first and second axial extremities. The first axial extrernity is carried on the wall of the passageway in the housing. The disc engages the second axial extremity of the flexible metallic seal in the closed position.
In many embodiments of the invention the periphery of the valve disc has clearance uith respect tO the passageway in the valve body.
In some forms of the invention the flexible metallic seal is dimensioned and configured to firmly engage the periphe~y of the disc. The disc may have a periphery having a generally arcuate cross-section. The periphery and the flexible metallic seal may be disposed in generally tangential abutting relationship. The first axial extremity of the % ~
f~exible metallic seal may be generally cylindrical and the second axial extremity of the flexible metallic seal may be generally bell shaped.
In other forms of the invention the valve body includes a lip spaced ~om the wall of the passageway and extending generally parallel to the centerline of the passageway.
l he lip may extend around the complete 360 degree extent of the passageway. The housing may include a clearance space proximate to second axial extremity of the flexible metallic seal whereby, the second axial extremity may move radially in response to engagement with the disc.
The second axial extremity~may extend in cantilevered relationship from the first axial extremity. The first axial extremity may be welded to the lip. In some embodiments of the invention the lip is dimensioned and configured to have substantially the same thermal mass as the first axial extremity of flexible metallic seal.
Various welding techniques may be used such as by a gas tungsten arc welding process, an electron beam welding process, a laser beam welding process, a plasma needle arc welding process, or a continuous resistance spot welding process.
BRIEF DESCRIPTION OF THE DRAWING
l'he invention will be better understood by reference to the accompanying drawing in which:
Figure 1 is a partially schematic side elevational view in partial section of a valve assembly in accordance with one form of the invention.
Figure 2 is a partially schematic plan view of the valve shown in Figure 1.
Figure 3 is a sectional view of the valve body for the valve shown in Figure 1.
Figure 4 is a partially schematic view of a valve and actuator assembly inco~porating the valve assembly shown in Figure 1.
Figure S is a fragmentaryview to an enlarged scale of the metallic seal shown in Figure 6.
Figure 6 is front elevational view of the metallic seal which is a part of the val~e assembly shown in Figure 1.
Figure 7 is a plan view of the metallic seal shown in Figure 6.
Figure 8 is a ~agmentary partially schematic view illustrating the manner of attachment of the metailic seat to the valve body in accordance with one embodiment of the invention~
Figure 9 is a view similar to Figure 8 showing the weld area in greater detail.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to Figures 1-7 there is shown a valve and actuator assembly 10 in accordance with one form of the invention.
The valve and actuator assembly 10 include an actuator assembly 12 and a valve assembly 14 that are joined by a coupling assembly 16.
The valve assembly 14 includes a valve body 18 having a bore 23 extending generally diametrically through a generally cylindrical passageway 18b. The bore 23 receives a shaft 22 on which is carried a butterfly or valve disc 24. More particularly, the shaft 2'2 includes a plurality of threaded bores 22a disposed in aligned relationship with a plurality of recesses 24a for receiving respective bolts to secure the butterny or valve disc 24 to the shaft 22. It will be seen that the valve is an offset or off center type butterfly valve in which the geometric center of the butterfly or valve disc 24 is not coincident with the shaft~ More particularly, the valve disc periphery 24b that bears aga nst the flexible metallic seal 26 is spaced from the shaft 22.
The valve assembly 14 also includes bushings 34, 34 carried within the valvc body 18 that support the shaft 22. A flexible graphite ring 30 is disposed around the shaft 2~
within the bore 23. A washer 31 is disposed betweerl the flexible graphite ring 30 and the valve body 18.
An actuator mounting flange 19 is provided on the valve body 18. The actuator mounting ~ange 1~ includes threaded bores 18a, 18a for accommodating the actuator.
The flexible metallic seal 26, as best seen in Figures 5-7 includes a generally cylindrical axial portion 26e and an axial extremity thereof 26d, which in various embodiments is bell shaped or ~ared and in others or even conical. As best seen in Figures 1 and 2 thc valve disc periphery 24b contacts the bell shaped axial section 26d of the flexible metallic seal 26. The flexible metallic seal 26 ordinarily will be manufacturcd of sheet metal.
It will be understood that the shape of the periphery 24d will be arcuate in some embodiments as described below and best shown in figure 2. The view of Figure 1 Yvill be understood to show a step adjacent to the periphery that engages one of the sleeves 34 at the tOp (as viewed~ of the passageway 18b. A similar step is provided adjacent to the other sleeve 34 adjacent to the bottom (as viewed) of the passageway 18b. This structure iimits ~xial movement of the sleeves 34, 34 toward the centerline of the passageway i~b.
It is preferable that the portion of the flexible metallic seal 26 that contacts tbe periphery 26d be disposed in tangential relationship to the arcuate cross-section of the periphery 26d. It will thus be seen that there is substantially line contact between the respective surfaces. Ordinarily, the arcuate cross-section of the periphery 24b of the disc 24 will be arc shaped and have a center of curvature coincident with a point on the centerline of the shaft 22 that is coincident with the centerline of the passagewa~ 18b.
2~&~ ~
Invarious embodiments of the invention the portion of the flexible metallic seal 26 that contacts the periphery 24b has an arcuate cross-section at the line of contact with the periphery 24b.
It will be understood that the flexible metallic seal 26 has the axial extremit~ of the cylindrical portion 26e has the extreme axial extremity thereof welded to the valve body 18. The valve body 18 may have a step for receiving the seal 26 as best shown in Figure 2. The valve body is also provided with radial clearance or a recess 40 to permit deformation of the bell shaped axial extremity 26d of the flexible metallic seal 26. The flexible metallic seal 26 relies on the hoop strength of the flexible metallic seal 26 as well as the cantilever effect, inherent in the weld at one alcial extremity with the other axial extremity (the free end) being disposed over the recess 40 of the flexible metallic seal 26. This construction also relies on the elasticity of the material of which the flexible metallic seal 26 is constructed.
The diameter of the butterfly or valve disc 24 has a diameter that is smallcr than the inside diameter of the passageway 18b because the seal is achieved betwecn the butterfly or valve disc 24 and the flexible metallic seal 26. Because of the clearance between the rigid butterfly or valve disc 24 and the rigid valve body 18 seizing of these two elements is prevented despite the wide temperature ranges in which the valve must function.
Ordinarily the flexible metallic seal 26 is secured to the valve body 18 at one axial extrenuty by a weld SQ. This weld may be achieved by a gas tungsten arc weldiDg process, an electron beam welding process, a laser beam welding process. a plasma needle arcweldingprocess or a continuous resistance (spot) weldingtechnique. These and other processes that also are characterized by high local intensity and low total heat input.
Such welding techniques are much less expensive than the clamping techniques used in prior art structures.
Because the relatively thin flexible metallic seal 26 is welded to the relatively thick valve body 18, as best seen in Figures 8 and 9, it is particularly important to rninimize heat input and distortion and to elirn~nate the need for filler material. In the preferred embodiment the valve body 18 has a axially (with respect to the valve body 18) extending lip 52. Ordinarily, the lip 52 is machined in the valve body 18. The lip 52 has approx~mately the same thermal mass as the axial extremity 26e of the flexible metallic seal 26.
With (1) this construction and (2) the welding processes referred to above the fusion zone is formed from the base metals of the valve body 18 and the fle~ble metallic seal 26. There is little or no distortion of the flexible metallic seal 26 and a good metallur-gically sound weld is achieved. lhus, a good seal with good structural integlity is achieved. This arrangement facilitates ease of providing fLxtures to hold tho valve body 18 and flexible metallic seal 26 during the welding process.
In the preferred embodirnent the valve body 18 is made of carbon steel. The shaft æ
and a washer 31 located below (as viewed) the flexible graphite ring 30 are stainless ~ fl~
steel. The butterfly orvalve disc 24 is made of nickel plated carbon steel. The bushings 34 are nickel plated carbon steel in the preferred embodiment. The flexible metallic seal 26 is forrned with heat treated nickel plated carbon steel in the preferred embodi-ment. In other embodiments of the invention the seal 26 may be made of various corrosion resistant materials such as stainless steel, InconeL Hastelloy, nickels alloys or various other materials. The shaft 22 may be plated carbon steel in other embodi-ments and the bushings 34 may be chrome or other materials.
The invention has been described with reference to its illustrated preferred embodi-ment. Persons skilled in the art of such devices may upon exposure to the teachings herein, conceive other variations. Such variations are deemed to be encompassed by the disclosure, the invention being delimited only by the following claims.
Having thus described my invention I claim:
The invention relates to valves and particularly to butter~y valves having particular application for the control of fluids at low pressure and high temperature. One such application is in exhaust systems of automobiles. For example, the valve in accordance with one form of the invention is used in an exhaust system for a diesel engine. More particularly, the system may utilize two such valves. Each valve is disposed in a pipe extending to one of t~,vo ~Iter systems. At any one instant one valve ;s open and the other is closed. Thus, one filter is operative to filter the exhaust gases and the other is heated to burn trapped contaminates inside the filter.
The prior art includes butterfly valves that have a metallic seat for use at high tempera-tures. One such valve is shown in United States patent 4,487,216 having the sameassignee as the present application. Typically, the metallic seal is generally annular and the valve is used to control a fluid at relatively high pressure. The design of such prior art valves tvpically has a wide ~ange and the valve uses a high pressure ~uid, in the order of 50 psi, to push the metallic seal against the periphery of the valve dis Other prior art diesel exhaust system valves have used a metal body in which the seat is machined. Typically the valve disc was thick and heavy. This relatively expensive construction was unsatisfactory because the valve allowed an excessive leakage be-tween the valve disc and the valve seat. An additional disadvantage was that the valve disc did not clean the valve seat when the valve was opened. Because the diesel exhaust 2 ~
contains substantial particulate matter, namely carbon black, the failure to clean the valve seat is particularly significant~ The accumulation of carbon black on the valve seat causes further increase in valve leakage.
Fhe body of prior art valves was considerably more massive than the closure member.
The closure member would expand faster than the valve body. The expansion of the valve body was restricted since, the outside temperature of the valve body was lower than the inside temperature of the valve body. Differences ben,veen the expansion of the valve body and the closure member caused the body and the closure member to seize together.
Prior art exhaust brake valves have been used with diesel engines. Such valves typically stopped the flow of exhaust gasses when the driver removed his foot from the ac-celerator pedal. The purpose of such valves was to slow the vehicle by causing increased engine braking. Such valves also had a high leak rate and did not clean the carbon deposits ~rom the valve seat when the valve opened.
The prior art flexible metallic seals have generally been secured to valvc housings by cl~nping arrangements that have lirnited radial movement of the seal and thus limited the precision with which the seal engaged the butterfly particularly where substantial pressures are not available to aid in urging the seal against the periphery of the buUerfly or valve disc~
2 ~
Stick or overlay welding techniques have been used to form a seat on a valve body. This technique forrns a weld bead on the valve body and that bead is machined to form thc valve seat~ This technique is relatively expensive. In addition, such arrangcmcnts arc subject to substantial leakage because of the inilexibility of the seat.
It is an object of the invention to provide a butterfly valve which will function to control a high temperature low pressure fluid. More particularly, it is an object of the invention to provide a valve that will function with fluids having a temperaturc rangc of -20 dcgrees Fahrcnheit to 1000 degrees Fahrenheit and a pressurc which is bctwcen approxirnately 1 and 5 psi.
Still another object of the in,vention is to provide a valve that will have a valve body and valve disc combination tbat~ill not result in inordinate expansion of one part, and thus degradation of valve operation, as hot ~uids initially pass through the valve.
It is an object of the present invention to provide a valvc which will automadcally clean the valve seat when thc valvc disc is opened~
It is yet another objca of thc invention to provide apparatus which is incxpcnsIve to manufacture~
It is still another object of the invention to provide apparatus which will utilize a sheet metal valve seat~
2 ~
SUMMARY OF THE INVENTION
It has now been found that these and other objects of the invention may be attained in a butterfly valve apparatus which includes a valve body hav~ng an interior wall defining a generally cylindrical passageway having a centerline. A shaft having a centerline extends generally diametrically through the valve body. The shaft is carried by the valve body to perrnit rotation with respect to the body. A valve disc is mounted on the shaft in offset relationship from the centerline of the shaft. The disc is movable between an open position in which the disc is aligned with the centerline of the passageway and a closed position in which the disc is disposed in perpendicular relationship to the centerline of the passageway. A flexible metallic seal has a generally cylindrical form and has first and second axial extremities. The first axial extrernity is carried on the wall of the passageway in the housing. The disc engages the second axial extremity of the flexible metallic seal in the closed position.
In many embodiments of the invention the periphery of the valve disc has clearance uith respect tO the passageway in the valve body.
In some forms of the invention the flexible metallic seal is dimensioned and configured to firmly engage the periphe~y of the disc. The disc may have a periphery having a generally arcuate cross-section. The periphery and the flexible metallic seal may be disposed in generally tangential abutting relationship. The first axial extremity of the % ~
f~exible metallic seal may be generally cylindrical and the second axial extremity of the flexible metallic seal may be generally bell shaped.
In other forms of the invention the valve body includes a lip spaced ~om the wall of the passageway and extending generally parallel to the centerline of the passageway.
l he lip may extend around the complete 360 degree extent of the passageway. The housing may include a clearance space proximate to second axial extremity of the flexible metallic seal whereby, the second axial extremity may move radially in response to engagement with the disc.
The second axial extremity~may extend in cantilevered relationship from the first axial extremity. The first axial extremity may be welded to the lip. In some embodiments of the invention the lip is dimensioned and configured to have substantially the same thermal mass as the first axial extremity of flexible metallic seal.
Various welding techniques may be used such as by a gas tungsten arc welding process, an electron beam welding process, a laser beam welding process, a plasma needle arc welding process, or a continuous resistance spot welding process.
BRIEF DESCRIPTION OF THE DRAWING
l'he invention will be better understood by reference to the accompanying drawing in which:
Figure 1 is a partially schematic side elevational view in partial section of a valve assembly in accordance with one form of the invention.
Figure 2 is a partially schematic plan view of the valve shown in Figure 1.
Figure 3 is a sectional view of the valve body for the valve shown in Figure 1.
Figure 4 is a partially schematic view of a valve and actuator assembly inco~porating the valve assembly shown in Figure 1.
Figure S is a fragmentaryview to an enlarged scale of the metallic seal shown in Figure 6.
Figure 6 is front elevational view of the metallic seal which is a part of the val~e assembly shown in Figure 1.
Figure 7 is a plan view of the metallic seal shown in Figure 6.
Figure 8 is a ~agmentary partially schematic view illustrating the manner of attachment of the metailic seat to the valve body in accordance with one embodiment of the invention~
Figure 9 is a view similar to Figure 8 showing the weld area in greater detail.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to Figures 1-7 there is shown a valve and actuator assembly 10 in accordance with one form of the invention.
The valve and actuator assembly 10 include an actuator assembly 12 and a valve assembly 14 that are joined by a coupling assembly 16.
The valve assembly 14 includes a valve body 18 having a bore 23 extending generally diametrically through a generally cylindrical passageway 18b. The bore 23 receives a shaft 22 on which is carried a butterfly or valve disc 24. More particularly, the shaft 2'2 includes a plurality of threaded bores 22a disposed in aligned relationship with a plurality of recesses 24a for receiving respective bolts to secure the butterny or valve disc 24 to the shaft 22. It will be seen that the valve is an offset or off center type butterfly valve in which the geometric center of the butterfly or valve disc 24 is not coincident with the shaft~ More particularly, the valve disc periphery 24b that bears aga nst the flexible metallic seal 26 is spaced from the shaft 22.
The valve assembly 14 also includes bushings 34, 34 carried within the valvc body 18 that support the shaft 22. A flexible graphite ring 30 is disposed around the shaft 2~
within the bore 23. A washer 31 is disposed betweerl the flexible graphite ring 30 and the valve body 18.
An actuator mounting flange 19 is provided on the valve body 18. The actuator mounting ~ange 1~ includes threaded bores 18a, 18a for accommodating the actuator.
The flexible metallic seal 26, as best seen in Figures 5-7 includes a generally cylindrical axial portion 26e and an axial extremity thereof 26d, which in various embodiments is bell shaped or ~ared and in others or even conical. As best seen in Figures 1 and 2 thc valve disc periphery 24b contacts the bell shaped axial section 26d of the flexible metallic seal 26. The flexible metallic seal 26 ordinarily will be manufacturcd of sheet metal.
It will be understood that the shape of the periphery 24d will be arcuate in some embodiments as described below and best shown in figure 2. The view of Figure 1 Yvill be understood to show a step adjacent to the periphery that engages one of the sleeves 34 at the tOp (as viewed~ of the passageway 18b. A similar step is provided adjacent to the other sleeve 34 adjacent to the bottom (as viewed) of the passageway 18b. This structure iimits ~xial movement of the sleeves 34, 34 toward the centerline of the passageway i~b.
It is preferable that the portion of the flexible metallic seal 26 that contacts tbe periphery 26d be disposed in tangential relationship to the arcuate cross-section of the periphery 26d. It will thus be seen that there is substantially line contact between the respective surfaces. Ordinarily, the arcuate cross-section of the periphery 24b of the disc 24 will be arc shaped and have a center of curvature coincident with a point on the centerline of the shaft 22 that is coincident with the centerline of the passagewa~ 18b.
2~&~ ~
Invarious embodiments of the invention the portion of the flexible metallic seal 26 that contacts the periphery 24b has an arcuate cross-section at the line of contact with the periphery 24b.
It will be understood that the flexible metallic seal 26 has the axial extremit~ of the cylindrical portion 26e has the extreme axial extremity thereof welded to the valve body 18. The valve body 18 may have a step for receiving the seal 26 as best shown in Figure 2. The valve body is also provided with radial clearance or a recess 40 to permit deformation of the bell shaped axial extremity 26d of the flexible metallic seal 26. The flexible metallic seal 26 relies on the hoop strength of the flexible metallic seal 26 as well as the cantilever effect, inherent in the weld at one alcial extremity with the other axial extremity (the free end) being disposed over the recess 40 of the flexible metallic seal 26. This construction also relies on the elasticity of the material of which the flexible metallic seal 26 is constructed.
The diameter of the butterfly or valve disc 24 has a diameter that is smallcr than the inside diameter of the passageway 18b because the seal is achieved betwecn the butterfly or valve disc 24 and the flexible metallic seal 26. Because of the clearance between the rigid butterfly or valve disc 24 and the rigid valve body 18 seizing of these two elements is prevented despite the wide temperature ranges in which the valve must function.
Ordinarily the flexible metallic seal 26 is secured to the valve body 18 at one axial extrenuty by a weld SQ. This weld may be achieved by a gas tungsten arc weldiDg process, an electron beam welding process, a laser beam welding process. a plasma needle arcweldingprocess or a continuous resistance (spot) weldingtechnique. These and other processes that also are characterized by high local intensity and low total heat input.
Such welding techniques are much less expensive than the clamping techniques used in prior art structures.
Because the relatively thin flexible metallic seal 26 is welded to the relatively thick valve body 18, as best seen in Figures 8 and 9, it is particularly important to rninimize heat input and distortion and to elirn~nate the need for filler material. In the preferred embodiment the valve body 18 has a axially (with respect to the valve body 18) extending lip 52. Ordinarily, the lip 52 is machined in the valve body 18. The lip 52 has approx~mately the same thermal mass as the axial extremity 26e of the flexible metallic seal 26.
With (1) this construction and (2) the welding processes referred to above the fusion zone is formed from the base metals of the valve body 18 and the fle~ble metallic seal 26. There is little or no distortion of the flexible metallic seal 26 and a good metallur-gically sound weld is achieved. lhus, a good seal with good structural integlity is achieved. This arrangement facilitates ease of providing fLxtures to hold tho valve body 18 and flexible metallic seal 26 during the welding process.
In the preferred embodirnent the valve body 18 is made of carbon steel. The shaft æ
and a washer 31 located below (as viewed) the flexible graphite ring 30 are stainless ~ fl~
steel. The butterfly orvalve disc 24 is made of nickel plated carbon steel. The bushings 34 are nickel plated carbon steel in the preferred embodiment. The flexible metallic seal 26 is forrned with heat treated nickel plated carbon steel in the preferred embodi-ment. In other embodiments of the invention the seal 26 may be made of various corrosion resistant materials such as stainless steel, InconeL Hastelloy, nickels alloys or various other materials. The shaft 22 may be plated carbon steel in other embodi-ments and the bushings 34 may be chrome or other materials.
The invention has been described with reference to its illustrated preferred embodi-ment. Persons skilled in the art of such devices may upon exposure to the teachings herein, conceive other variations. Such variations are deemed to be encompassed by the disclosure, the invention being delimited only by the following claims.
Having thus described my invention I claim:
Claims (24)
1. A butterfly valve apparatus which comprises:
a valve body having an interior wall defining a generally cylindrical passageway having a centerline;
a shaft having a centerline extending generally diametrically through said valve body, said shaft being carried by said valve body to permit rotation with respect to said body;
a valve disc mounted on said shaft in offset relationship from the centerline of said shaft, said disc being movable between an open position in which said disc is aligned with said centerline of said passageway and a closed position in which said disc is disposed in perpendicular relationship to said centerline of said passageway a flexible metallic seal having a generally cylindrical form having first and second axial extremities, said first axial extremity being carried on said wall of said passageway in said housing, said disc engaging said second axial extremity of said flexible metallic seal in said closed position.
a valve body having an interior wall defining a generally cylindrical passageway having a centerline;
a shaft having a centerline extending generally diametrically through said valve body, said shaft being carried by said valve body to permit rotation with respect to said body;
a valve disc mounted on said shaft in offset relationship from the centerline of said shaft, said disc being movable between an open position in which said disc is aligned with said centerline of said passageway and a closed position in which said disc is disposed in perpendicular relationship to said centerline of said passageway a flexible metallic seal having a generally cylindrical form having first and second axial extremities, said first axial extremity being carried on said wall of said passageway in said housing, said disc engaging said second axial extremity of said flexible metallic seal in said closed position.
2. The apparatus as described in claim 1 wherein:
said flexible metallic seal is dimensioned and configured to firmly engage the periphery of said disc.
said flexible metallic seal is dimensioned and configured to firmly engage the periphery of said disc.
3. The apparatus as described in claim 2 wherein:
said disc has a periphery having a generally arcuate cross-section.
said disc has a periphery having a generally arcuate cross-section.
4. The apparatus as described in claim 3 wherein:
said periphery and said flexible metallic seal are disposed in generally tangential abutting relationship.
said periphery and said flexible metallic seal are disposed in generally tangential abutting relationship.
5. The apparatus as described in claim 4 wherein:
said first axial extremity of said flexible metallic seal is generally cylindrical.
said first axial extremity of said flexible metallic seal is generally cylindrical.
6. The apparatus as described in claim S wherein:
said second axial extremity of said flexible metallic seal is generally bell shaped.
said second axial extremity of said flexible metallic seal is generally bell shaped.
7. The apparatus as described in claim 6 wherein:
said valve body includes a lip spaced from said wall of said passageway and extending generally parallel to said centerline of said passageway.
said valve body includes a lip spaced from said wall of said passageway and extending generally parallel to said centerline of said passageway.
8. The apparatus as described in claim 7 wherein:
lip extends around the complete 360 degree extent of said passageway.
lip extends around the complete 360 degree extent of said passageway.
9. The apparatus as described in claim 8 wherein:
said housing includes a clearance space proximate to second axial extremity of said flexible metallic seal whereby, said second axial extremity may move radially inresponse to engagement with said disc.
said housing includes a clearance space proximate to second axial extremity of said flexible metallic seal whereby, said second axial extremity may move radially inresponse to engagement with said disc.
10. The apparatus as described in claim 9 wherein:
said second axial extremity extends in cantilevered relationship from said first axial extremity.
said second axial extremity extends in cantilevered relationship from said first axial extremity.
11. The apparatus as described in claim 10 wherein:
said first axial extremity is welded to said lip.
said first axial extremity is welded to said lip.
12. The apparatus as described in claim 11 wherein:
said lip is dimensioned and configured to have substantially the same thermal mass as said first axial extremity of flexible metallic seal.
said lip is dimensioned and configured to have substantially the same thermal mass as said first axial extremity of flexible metallic seal.
13. The apparatus as described in claim 12 wherein:
said first axial extremity is welded to said lip by a gas tungsten arc welding process.
said first axial extremity is welded to said lip by a gas tungsten arc welding process.
14. The apparatus as described in claim 12 wherein:
said first axial extremity is welded to said lip by an electron beam welding process.
said first axial extremity is welded to said lip by an electron beam welding process.
15. The apparatus as described in claim 14 wherein:
said first axial extremity is welded to said lip by a laser beam welding process.
said first axial extremity is welded to said lip by a laser beam welding process.
16. The apparatus as described in claim 12 wherein:
said first axial extremity is welded to said lip by a plasma needle arc welding process.
said first axial extremity is welded to said lip by a plasma needle arc welding process.
17. The apparatus as described in claim 12 wherein:
said first axial extremity is welded to said lip by a continuous resistance spot welding process.
said first axial extremity is welded to said lip by a continuous resistance spot welding process.
18. The apparatus as described in claim 1 wherein:
the periphery of said valve disc has clearance with respect to said passageway in said valve body.
the periphery of said valve disc has clearance with respect to said passageway in said valve body.
19. The apparatus as described in claim 2 wherein:
said disc has a periphery having a generally arcuate cross-section and said seal has a generally arcuate cross section is the portion thereof engaging said periphery in the closed position of said disc.
said disc has a periphery having a generally arcuate cross-section and said seal has a generally arcuate cross section is the portion thereof engaging said periphery in the closed position of said disc.
20. The apparatus as described in claim 2 wherein:
said periphery and said flexible metallic seal have substantially line contact therebet-ween.
said periphery and said flexible metallic seal have substantially line contact therebet-ween.
21. The apparatus as described in claim 19 wherein:
said first axial extremity of said flexible metallic seal is generally cylindrical.
said first axial extremity of said flexible metallic seal is generally cylindrical.
22. The apparatus as described in claim 20 wherein:
said first axial extremity of said flexible metallic seal is generally cylindrical.
said first axial extremity of said flexible metallic seal is generally cylindrical.
23. The apparatus as described in claim 5 wherein:
said second axial extremity of said flexible metallic seal is generally conical.
said second axial extremity of said flexible metallic seal is generally conical.
24. The apparatus as described in claim 1 wherein:
said valve body having a recess on said interior wall dimensioned for receiving said first axial extremity of said flexible metallic seal.
said valve body having a recess on said interior wall dimensioned for receiving said first axial extremity of said flexible metallic seal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2054610 CA2054610A1 (en) | 1991-10-31 | 1991-10-31 | Valve for low pressure high temperature applications |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2054610 CA2054610A1 (en) | 1991-10-31 | 1991-10-31 | Valve for low pressure high temperature applications |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2054610A1 true CA2054610A1 (en) | 1993-05-01 |
Family
ID=4148675
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2054610 Abandoned CA2054610A1 (en) | 1991-10-31 | 1991-10-31 | Valve for low pressure high temperature applications |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2054610A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5839717A (en) * | 1997-03-25 | 1998-11-24 | Feigel; Kurt R. | Valve with improved shaft retainer |
-
1991
- 1991-10-31 CA CA 2054610 patent/CA2054610A1/en not_active Abandoned
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5839717A (en) * | 1997-03-25 | 1998-11-24 | Feigel; Kurt R. | Valve with improved shaft retainer |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5630593A (en) | Pressure-energized sealing rings | |
| US3894718A (en) | Ball valve | |
| US9587747B2 (en) | Flexible seals for process control valves | |
| US5799954A (en) | Coaxial sealing ring | |
| US4457523A (en) | Torsionally flexible metallic annular seal | |
| US7837233B2 (en) | Exhaust system slip joint | |
| US4217923A (en) | Ball valve with readily removable ball and seats for high temperature environment | |
| US5683119A (en) | Pipe joint and seal therefor | |
| JP5128490B2 (en) | Flexible seals for process control valves | |
| US20040159819A1 (en) | Ball valve seat seal | |
| EP0242868B1 (en) | Joint means having flanges | |
| CA2401601A1 (en) | Pipe joint and seal | |
| US5730445A (en) | Pressure energized metalic sealing ring | |
| US4337920A (en) | Valve | |
| JPH0384268A (en) | Rotary valve with seal | |
| US3250510A (en) | Self-adjustable seats for butterfly valves or the like | |
| CA1212094A (en) | Valve seal for fire safe or high temperature valves | |
| US5518280A (en) | Seal for an exhaust system | |
| NL8102969A (en) | SEALS FOR PIPES. | |
| CA2054610A1 (en) | Valve for low pressure high temperature applications | |
| US5934647A (en) | Metal seal for valve | |
| US5467966A (en) | Seals | |
| US3334926A (en) | Ball pipe joint | |
| US6612584B1 (en) | Flange and seal assembly | |
| JP2002089724A (en) | Sealing member and valve using it |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |