CA1179664A - Low emission valve - Google Patents
Low emission valveInfo
- Publication number
- CA1179664A CA1179664A CA000394051A CA394051A CA1179664A CA 1179664 A CA1179664 A CA 1179664A CA 000394051 A CA000394051 A CA 000394051A CA 394051 A CA394051 A CA 394051A CA 1179664 A CA1179664 A CA 1179664A
- Authority
- CA
- Canada
- Prior art keywords
- seal
- valve
- annular
- stem
- chamber
- 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
- F16K41/00—Spindle sealings
- F16K41/10—Spindle sealings with diaphragm, e.g. shaped as bellows or tube
-
- 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
- F16K41/00—Spindle sealings
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Details Of Valves (AREA)
Abstract
LOW EMISSION VALVE
Abstract:
A low emission valve incorporating a mechanical seal assembly (66) to substantially eliminate emissions of fluids to the atmosphere, the valve being particularly adaptable for use in the chemical processing industry where emissions of organic fluids to the atmosphere has been a problem.
Abstract:
A low emission valve incorporating a mechanical seal assembly (66) to substantially eliminate emissions of fluids to the atmosphere, the valve being particularly adaptable for use in the chemical processing industry where emissions of organic fluids to the atmosphere has been a problem.
Description
~.~'7~
This invention relates to a valve o~ thé type used for controlling the flow of fluid.
In the chemical process industry, especially in the petrochemical and hydrocarbon refinery areas, the emission of volatile organic hydrocarbon fluids, such as gases, to the atmosphere has been a problem. One of the leakage sources is from various valves used in the processing apparatus. Most of these valves are constructed with packings along the stems, but the stems must turn when the valve is operated. To prevent leakage along the valve stems, the packing must be tightened against the valve stems. This induces high friction contact along the stems and makes the valves difficult to operate.
According to the present invention there is provided a valve for controlling the flow of a fluid, the valve includin~ a body defining a valve chamber an~
having inlet and outlet connections, and a bonnet connected to the body and further defining-the valve chamber. A
turnable valve stem passes through and projects from the body and bonnet, and a valve closure element i5 provided in the valve chamber connected to the stem so that upon turning the stem the valve element moves between valve open and closed positions, the closed position being defined when the closure element is in the position to block the inlet and outlet connections and the open position being defined when the closwre element is in a position removed from the inlet and outlet connections. An annular collar means surrounds the stem and is connected to the bonnet, the annular collar means having a cavity therein and defining an annular seal chamber. A mechanical seal assembly surrounds the stem and is disposed in the annular seal chamber, the mechanical seal assembly being so constructed and arranged for insertion as a unit into the annular seal cavity and for removal and replacement as a unit therefrom. The mechanical seal assembly includes an annular disc surrounding and connected from rotation with the stem, the disc having a pair of lapped faces, each face defining a seal face. The mechanical seal ~' ;~
~7~
assembly also includes a pair o e annular seal rings and a bellows connected to each of the seal rings o~ the paix, each seal ring having a lapped seal face, and each ring seal face contacting one of the seal faces of the disc.
The bellows is so constructed and arranged to resiliently urge its connected seal ring toward the annular disc and is further so constructed and arranged to restrict leakage of fluid from the valve and along the stem to leakage across the contacting seal faces. The contact seal faces are relatively rotatable with respect o each other only when the stem is rotated.
One way of carrying out the invention is described in detail below with reference to drawings which illustrate only one specific embodiment, in which:-Fig. l is a section through a valve assembly constructed according to this invention; and Fig. 2 is a section through a second embodiment of a valve assembly constructed according to this invention.
A low emission valve assembly 10, constructed according to this invention, is illustrated in Fig. l of the drawing~ The valve assembly 10 comprises a valve body 12 formed with a flow passage 14 and a generally cylindrical valve chamber 16. The passage l~ has opposed inlet and outlet openings 18 and 20, respectively, and inserts 22 and
This invention relates to a valve o~ thé type used for controlling the flow of fluid.
In the chemical process industry, especially in the petrochemical and hydrocarbon refinery areas, the emission of volatile organic hydrocarbon fluids, such as gases, to the atmosphere has been a problem. One of the leakage sources is from various valves used in the processing apparatus. Most of these valves are constructed with packings along the stems, but the stems must turn when the valve is operated. To prevent leakage along the valve stems, the packing must be tightened against the valve stems. This induces high friction contact along the stems and makes the valves difficult to operate.
According to the present invention there is provided a valve for controlling the flow of a fluid, the valve includin~ a body defining a valve chamber an~
having inlet and outlet connections, and a bonnet connected to the body and further defining-the valve chamber. A
turnable valve stem passes through and projects from the body and bonnet, and a valve closure element i5 provided in the valve chamber connected to the stem so that upon turning the stem the valve element moves between valve open and closed positions, the closed position being defined when the closure element is in the position to block the inlet and outlet connections and the open position being defined when the closwre element is in a position removed from the inlet and outlet connections. An annular collar means surrounds the stem and is connected to the bonnet, the annular collar means having a cavity therein and defining an annular seal chamber. A mechanical seal assembly surrounds the stem and is disposed in the annular seal chamber, the mechanical seal assembly being so constructed and arranged for insertion as a unit into the annular seal cavity and for removal and replacement as a unit therefrom. The mechanical seal assembly includes an annular disc surrounding and connected from rotation with the stem, the disc having a pair of lapped faces, each face defining a seal face. The mechanical seal ~' ;~
~7~
assembly also includes a pair o e annular seal rings and a bellows connected to each of the seal rings o~ the paix, each seal ring having a lapped seal face, and each ring seal face contacting one of the seal faces of the disc.
The bellows is so constructed and arranged to resiliently urge its connected seal ring toward the annular disc and is further so constructed and arranged to restrict leakage of fluid from the valve and along the stem to leakage across the contacting seal faces. The contact seal faces are relatively rotatable with respect o each other only when the stem is rotated.
One way of carrying out the invention is described in detail below with reference to drawings which illustrate only one specific embodiment, in which:-Fig. l is a section through a valve assembly constructed according to this invention; and Fig. 2 is a section through a second embodiment of a valve assembly constructed according to this invention.
A low emission valve assembly 10, constructed according to this invention, is illustrated in Fig. l of the drawing~ The valve assembly 10 comprises a valve body 12 formed with a flow passage 14 and a generally cylindrical valve chamber 16. The passage l~ has opposed inlet and outlet openings 18 and 20, respectively, and inserts 22 and
2~ therein, each defining a valve seat 26 and 28, respectively, the valve seats being within the chamber 16. 'I'he inlet and outlet openings 18 and 20 can also ~unction as outlet and inlet openings, respectively. A gate 30 is located in the chamber 16 and it is formed with "
~ 4~
opposed ~aces 32 and 34 which are adapted to seat on the val~e seats 26 and 28, respectively. The gate 30 is formed with a shank 36 carrying an internally threaded insert 38 located upwardly ~rom the gate faces 32 and 34. The shank 36 and insert 38 receive a valve stem 40 having external threads 42 mating with the threads of the insert 38. As can be readily seen, rotation of -the stem 40 causes the gate 30 to move axially, either up or down, de-pending on the direction o~ rotation o~ the stem, the stem remaining in the position illustrated.
At its terminal end, -the stem 40 is provided with a handle 44 to turn the stem 40. The handle 44 is retained on the stem 40 by a nut 46 recei~ed on a threaded portion of the stem.
A bonnet 50 is bolted or otherwise secured to the body; it has a cavity 52 communicating with the chamber 16 o~ the body 12 and a central opening through which the stem 40 passes. The cavi-ty 52 is provided wlth a back seat 54 upon which -the terminal end 56 o~ the shank 36 o~ the gate 30 seats when the gate 30 is in its uppermost position. The bonnet 50 is ~ormed to provide a cavity 58 to support parts o~ a thrust bearing assembly 60, and a cavity 62 to receive a seal retaining collar 64. The collar 64 is connected, as by being welded (as illustrated in Fig. 1), bolted or otherwise secured to the bonnet and retains parts o~ a mechanical seal arrangement 66 to be described. To remove the collar 64 ~rom the bonnet in the Fig. 1 embodiment, it is necessary to unweld the collar and bonnet.
The thrust bearing assembly 60 comprises a pair of thrust bushings 68, 70 shaped to receive a generally annular stem retainer 72 which is connected to the stem 40. The collar 64 has a lower annular lip 74 which abuts the upper surface o~ the thrust bushing 68, the retainer being threadably received in the bonnet 50 or bolted thereto.
The collar 64 is provided with a cavity 76 defined in part by the lip 74, the cavity 76 re-ceiving the mechanical seal arrangement 66. The seal arrangement 66 comprises an upper ssal ring 78 and a lower seal ring 80 each having a lapped seal face 82, 84~ respectively engaging respective lapped seal ~aces 86, 88 of a seal rotor 90 connected to the stem 40. Relative rotation between the en-gaging seal ~aces occurs only when -the stem is ro-tated. The seal rings and seal rotor can be con-structed of materials ~rom which conventional, prior ar,t mechanical seal rings are constructed.
A bellows 92 is welded or otherwise secl1red at one end to the upp~r seal ring 78 and to a re~
tainer 94 at the other end. A bellows 96 is welded or otherwise secured at one end -to the lower seal ring 80 and is welded to a retainer 97 received in the cavity 76 at its other end. The retainer 94 is received ln a cavity 98 in the collar 64 and-the seal assembly 66 is secured in position by a collar 100 threadably received on a portion of the stem 40.
The bellows 92 and 96 may be formed of a plurality of annular plates alternately welded together at the inner and outer circumferences or alternately may be formed of conventional seamless annular corrugated tubing of materials as known in the art.
~7~
~ 5 --The bellows 92 and 96 are installed to re-siliently urge the seal rings to which they are welded toward the rotor 90, so that the respective seal ~aces are in sealing relationship with one another. A leakoff connection 102 is provided in the collar 64 which communicates with the cavity ?6 such that any leakage across the seal ~aces 84, 88 can be removed; the connection 102 can be used to monitor leakage and emissions, i~ desired.
The mechanical seal assembIy 667 as can be seen, is modular in construction and can be removed and replaced, as a unit, even when the valve is operational. For example, i~ the valve is open, the gate can be seated on seat 54 permitting repair and/or replacement of the thrust bushings and/or the seal assembly.
In the event of iailure o~ the lowex position o~ the seal, i.e., the ring 80 and its face 84, the port 102 can be closed and the upper posi.-tion O:e the seal including the rlng 78 and the ~ace~ 82 and 86 becorne operational as a secondary seal, still substantially preventing emission O:e ~luids to the ~tmosphere.
Fig. 2 illustrates ano-ther embodiment o~ the valve differing mainly in the construction of the collar, identi~ied here as 110, the like parts of the valve assembly being identiiied as in Fig. 1. The collar 110 is constructed to be bolted, as by bolts 112, to the bonnet 50 and comprises a generally inverted cup-like portion 114 to which is connected, as by welding, a ring 116. The lower bellows 96 is connected to the ring 16 while the upper bellows 92 is connected as by welding to the portion 114.
A port 116 is formed in the portion 114, the function o~ which is the same as the port 102 of ~ig. 1.
A hex head nut member 118 is provided to contact the top of the rotor 90 and to locate a sleeve 120 for the passage of the stem 40. As readily seen, the operation of this embodiment is substantially the same as that of the ~ig. 1 embodiment.
The types and kinds of materials to be used for constructing the described valve-seal assembly are within the skill of one skilled in the art.
Preferably, the materials chosen should be corrosion resistant and where parts are welded, they should be of weldable materials. The choice of materials can also depend upon temperature considera-tion~
within the knowledge o~ one skilled in the art.
~ 4~
opposed ~aces 32 and 34 which are adapted to seat on the val~e seats 26 and 28, respectively. The gate 30 is formed with a shank 36 carrying an internally threaded insert 38 located upwardly ~rom the gate faces 32 and 34. The shank 36 and insert 38 receive a valve stem 40 having external threads 42 mating with the threads of the insert 38. As can be readily seen, rotation of -the stem 40 causes the gate 30 to move axially, either up or down, de-pending on the direction o~ rotation o~ the stem, the stem remaining in the position illustrated.
At its terminal end, -the stem 40 is provided with a handle 44 to turn the stem 40. The handle 44 is retained on the stem 40 by a nut 46 recei~ed on a threaded portion of the stem.
A bonnet 50 is bolted or otherwise secured to the body; it has a cavity 52 communicating with the chamber 16 o~ the body 12 and a central opening through which the stem 40 passes. The cavi-ty 52 is provided wlth a back seat 54 upon which -the terminal end 56 o~ the shank 36 o~ the gate 30 seats when the gate 30 is in its uppermost position. The bonnet 50 is ~ormed to provide a cavity 58 to support parts o~ a thrust bearing assembly 60, and a cavity 62 to receive a seal retaining collar 64. The collar 64 is connected, as by being welded (as illustrated in Fig. 1), bolted or otherwise secured to the bonnet and retains parts o~ a mechanical seal arrangement 66 to be described. To remove the collar 64 ~rom the bonnet in the Fig. 1 embodiment, it is necessary to unweld the collar and bonnet.
The thrust bearing assembly 60 comprises a pair of thrust bushings 68, 70 shaped to receive a generally annular stem retainer 72 which is connected to the stem 40. The collar 64 has a lower annular lip 74 which abuts the upper surface o~ the thrust bushing 68, the retainer being threadably received in the bonnet 50 or bolted thereto.
The collar 64 is provided with a cavity 76 defined in part by the lip 74, the cavity 76 re-ceiving the mechanical seal arrangement 66. The seal arrangement 66 comprises an upper ssal ring 78 and a lower seal ring 80 each having a lapped seal face 82, 84~ respectively engaging respective lapped seal ~aces 86, 88 of a seal rotor 90 connected to the stem 40. Relative rotation between the en-gaging seal ~aces occurs only when -the stem is ro-tated. The seal rings and seal rotor can be con-structed of materials ~rom which conventional, prior ar,t mechanical seal rings are constructed.
A bellows 92 is welded or otherwise secl1red at one end to the upp~r seal ring 78 and to a re~
tainer 94 at the other end. A bellows 96 is welded or otherwise secured at one end -to the lower seal ring 80 and is welded to a retainer 97 received in the cavity 76 at its other end. The retainer 94 is received ln a cavity 98 in the collar 64 and-the seal assembly 66 is secured in position by a collar 100 threadably received on a portion of the stem 40.
The bellows 92 and 96 may be formed of a plurality of annular plates alternately welded together at the inner and outer circumferences or alternately may be formed of conventional seamless annular corrugated tubing of materials as known in the art.
~7~
~ 5 --The bellows 92 and 96 are installed to re-siliently urge the seal rings to which they are welded toward the rotor 90, so that the respective seal ~aces are in sealing relationship with one another. A leakoff connection 102 is provided in the collar 64 which communicates with the cavity ?6 such that any leakage across the seal ~aces 84, 88 can be removed; the connection 102 can be used to monitor leakage and emissions, i~ desired.
The mechanical seal assembIy 667 as can be seen, is modular in construction and can be removed and replaced, as a unit, even when the valve is operational. For example, i~ the valve is open, the gate can be seated on seat 54 permitting repair and/or replacement of the thrust bushings and/or the seal assembly.
In the event of iailure o~ the lowex position o~ the seal, i.e., the ring 80 and its face 84, the port 102 can be closed and the upper posi.-tion O:e the seal including the rlng 78 and the ~ace~ 82 and 86 becorne operational as a secondary seal, still substantially preventing emission O:e ~luids to the ~tmosphere.
Fig. 2 illustrates ano-ther embodiment o~ the valve differing mainly in the construction of the collar, identi~ied here as 110, the like parts of the valve assembly being identiiied as in Fig. 1. The collar 110 is constructed to be bolted, as by bolts 112, to the bonnet 50 and comprises a generally inverted cup-like portion 114 to which is connected, as by welding, a ring 116. The lower bellows 96 is connected to the ring 16 while the upper bellows 92 is connected as by welding to the portion 114.
A port 116 is formed in the portion 114, the function o~ which is the same as the port 102 of ~ig. 1.
A hex head nut member 118 is provided to contact the top of the rotor 90 and to locate a sleeve 120 for the passage of the stem 40. As readily seen, the operation of this embodiment is substantially the same as that of the ~ig. 1 embodiment.
The types and kinds of materials to be used for constructing the described valve-seal assembly are within the skill of one skilled in the art.
Preferably, the materials chosen should be corrosion resistant and where parts are welded, they should be of weldable materials. The choice of materials can also depend upon temperature considera-tion~
within the knowledge o~ one skilled in the art.
Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A valve for controlling the flow of a fluid comprising:
a body defining a valve chamber and having inlet and outlet connections;
a bonnet connected to said body and further defining said valve chamber;
a turnable valve steam passing through and projecting from said body and bonnet;
a valve closure element in said valve chamber connected to said stem whereby upon turning said stem said closure element moves between valve open and closed positions, said closed position being defined when said closure element is in position to block said inlet and outlet connections and said open position being defined when said closure element is in a position removed from said inlet and outlet connections;
an annular collar means surrounding said stem and connected to said bonnet, said annular collar means having a cavity therein and defining an annular seal chamber; and a mechanical seal assembly surrounding said stem and disposed in said annular seal chamber, said mechanical seal assembly being so constructed and arranged for insertion as a unit into said annular seal cavity and for removal and replacement as a unit therefrom;
said mechanical seal assembly comprising an annular disc surrounding and connected for rotation with said stem, said disc having a pair of lapped faces, each face defining a seal face;
said mechanical seal assembly further comprising a pair of annular seal rings and a bellows connected to each of said seal rings of said pair, each seal ring having a lapped seal face and each seal ring seal face contacting one of said seal faces of said disc, said bellows being so constructed and arranged to resiliently urge its connected seal ring toward said annular disc and being further so constructed and arranged to restrict leakage of fluid from said valve and along said stem to leakage across said contacting seal faces, said contacting seal faces being relatively rotatable with respect to each other only when said stem is rotatable.
a body defining a valve chamber and having inlet and outlet connections;
a bonnet connected to said body and further defining said valve chamber;
a turnable valve steam passing through and projecting from said body and bonnet;
a valve closure element in said valve chamber connected to said stem whereby upon turning said stem said closure element moves between valve open and closed positions, said closed position being defined when said closure element is in position to block said inlet and outlet connections and said open position being defined when said closure element is in a position removed from said inlet and outlet connections;
an annular collar means surrounding said stem and connected to said bonnet, said annular collar means having a cavity therein and defining an annular seal chamber; and a mechanical seal assembly surrounding said stem and disposed in said annular seal chamber, said mechanical seal assembly being so constructed and arranged for insertion as a unit into said annular seal cavity and for removal and replacement as a unit therefrom;
said mechanical seal assembly comprising an annular disc surrounding and connected for rotation with said stem, said disc having a pair of lapped faces, each face defining a seal face;
said mechanical seal assembly further comprising a pair of annular seal rings and a bellows connected to each of said seal rings of said pair, each seal ring having a lapped seal face and each seal ring seal face contacting one of said seal faces of said disc, said bellows being so constructed and arranged to resiliently urge its connected seal ring toward said annular disc and being further so constructed and arranged to restrict leakage of fluid from said valve and along said stem to leakage across said contacting seal faces, said contacting seal faces being relatively rotatable with respect to each other only when said stem is rotatable.
2. A valve as recited in claim 1 further comprising a pair of spaced annular retainer means, each received in said seal chamber on an opposite side of said annular disc, one of said bellows and its seal ring being connected to each of said retainer means, one of said retainer means forming a cover for said annular seal chamber.
3. A valve as recited in claim 1 further comprising an annular retainer means surrounding said stem and received in said seal chamber on one side of said annular disc, one of said bellows and its seal ring being connected to said retainer, the other of said bellows and its seal ring being connected to a portion of said annular collar means, said annular collar means positioning said retainer means in said seal chamber.
4. A valve as recited in claim 1, further comprising an outlet passage in said collar means for removal of fluid leakage across said seal faces.
5. A valve as recited in claim 1, wherein said closure element comprises a gate element, and further comprising a seat located in said bonnet and surrounding said stem on which said gate element can seat when said gate element is in its open position, said gate element thereby sealing said valve chamber such that substantially no leakage can occur from said valve chamber along said stem and permitting repair and replacement of said mechanical seal assembly while said valve is operational.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US22938181A | 1981-01-28 | 1981-01-28 | |
| US229,381 | 1981-01-28 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1179664A true CA1179664A (en) | 1984-12-18 |
Family
ID=22860989
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000394051A Expired CA1179664A (en) | 1981-01-28 | 1982-01-13 | Low emission valve |
Country Status (3)
| Country | Link |
|---|---|
| CA (1) | CA1179664A (en) |
| FR (1) | FR2498725A1 (en) |
| IT (1) | IT8219265A0 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4537385A (en) * | 1982-10-14 | 1985-08-27 | Borg-Warner Corporation | Low emission valve |
-
1982
- 1982-01-13 CA CA000394051A patent/CA1179664A/en not_active Expired
- 1982-01-25 IT IT8219265A patent/IT8219265A0/en unknown
- 1982-01-27 FR FR8201270A patent/FR2498725A1/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| FR2498725A1 (en) | 1982-07-30 |
| IT8219265A0 (en) | 1982-01-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1291105C (en) | Inverted bellows valve | |
| US4458543A (en) | Cleanable sampling valve | |
| EP0060238B1 (en) | Valve stem packing structure | |
| EP0397725B1 (en) | Spring and seat assembly for ball valves | |
| US6082707A (en) | Valve seat and method | |
| US3150681A (en) | Ball valve | |
| US3761052A (en) | Flow plugger valve | |
| US5906354A (en) | Ball valve for lethal gas or fluid service | |
| JP2008286398A (en) | Switch valve | |
| US4294427A (en) | Mono-seat gate valve | |
| US4469123A (en) | Cold box valve | |
| US4179099A (en) | Expanding gate valve | |
| US4541608A (en) | High pressure shut-off valve | |
| WO2001033119A1 (en) | Compact manifold ball valve | |
| US3515371A (en) | Valve and valve seat | |
| US4033550A (en) | Water gate valve | |
| US3951380A (en) | Demountable valve | |
| US3763880A (en) | Gate valve structure | |
| US5503180A (en) | Valve having easily replaceable seat | |
| US4164236A (en) | Valve assembly with seat cleaning system | |
| EP0653032A4 (en) | Valve seat for high temperature valve. | |
| EP0848793B1 (en) | Hemispherical ball valve | |
| US3198484A (en) | Sheet metal valve construction | |
| CA1179664A (en) | Low emission valve | |
| US4537385A (en) | Low emission valve |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEC | Expiry (correction) | ||
| MKEX | Expiry |