GB2384286A - Sealing system for valve stem - Google Patents
Sealing system for valve stem Download PDFInfo
- Publication number
- GB2384286A GB2384286A GB0226562A GB0226562A GB2384286A GB 2384286 A GB2384286 A GB 2384286A GB 0226562 A GB0226562 A GB 0226562A GB 0226562 A GB0226562 A GB 0226562A GB 2384286 A GB2384286 A GB 2384286A
- Authority
- GB
- United Kingdom
- Prior art keywords
- seal
- sealing system
- valve body
- valve stem
- 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.)
- Withdrawn
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
- F16K5/0694—Spindle sealings
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Taps Or Cocks (AREA)
Abstract
A sealing system for a valve stem 16 in a rotary fluid valve, for example a ball valve, prevents leakage of pressurised fluid within the valve body to the environment under both high and low pressure conditions. The sealing system comprises oppositely facing seal faces 24,28 of hardened metal provided on the valve stem 16 and valve body 10 respectively. The seal members are located such that they are in abutment and at least one seal member being arranged to be urged by fluid pressure within the valve body towards the other seal member. Also incorporated is a static metal C-seal between seal ring 26 and valve body 10. A resilient lip seal 38 may also be provided.
Description
<Desc/Clms Page number 1>
"Sealing System for Valve Stem" This invention relates to a sealing system for the valve stem in a rotary fluid valve, for example a ball valve.
The invention seeks to provide a sealing system which is reliable and rugged, provides minimal (effectively zero) leakage, and maintains zero leakage for both gas and liquid flows under all
pressure conditions from low pressure (25psi/172kPa) to high pressure (15, OOOpsi/103MPa or above).
Accordingly, the present invention provides a sealing system for a rotary valve stem, the sealing system comprising a first seal member located on the valve stem and providing an annular, upwardly facing seal face of hardened metal, a second seal member located on the valve body and providing an annular, downwardly facing seal face of hardened metal, the first and second seal members being located such that said seal faces are in abutment, and at least
<Desc/Clms Page number 2>
one of said seal members being arranged to be urged by fluid pressure within the valve body towards the other seal member.
Preferably the first seal member comprises an annular flange formed on or secured to the valve stem, and the second seal member comprises a ring seated in a recess in the valve body.
Preferably also, a static metal seal, such as a metal"C"seal, is located between the ring and the valve body.
The seal faces are preferably preloaded together, suitably by spring means acting between the valve stem and the valve body.
One or more bushes may be provided between the valve stem and the valve body for rotational guidance and support of the valve stem.
A secondary seal may be provided, for example a resilient lip seal, and this may conveniently be located between a pair of said bushes.
An embodiment of the invention will now be described, by way of example only, with reference to the drawing in which the single figure is a partial cross-section of a ball valve incorporating the invention.
<Desc/Clms Page number 3>
Referring to the drawing, a ball valve comprises a valve body or bonnet 10 and a valve ball 12 having a through bore 14. The ball 12 is drivingly connected to a valve stem 16 by which the ball 12 can be rotated in a seat (not shown) in the valve body 10 between valve open and valve closed positions. The connection between the ball 12 and the valve stem 16 is by means of interfitting shapes such as square or hex, as indicated at 18, which provide rotational coupling while permitting relative axial movement.
The valve stem 16 must be provided with a sealing system which is capable of accommodating rotation and which is effective to prevent leakage of the pressurised fluid within the valve body 10 to the environment.
The sealing system comprises a primary metal seal system designated generally at 20. The system 20 includes a flange 22 formed on the valve stem 16 and having an annular top surface 24 which is hardened and acts as a seal face. A seal ring 26 is formed to provide a lower annular surface 28 which is hardened and bears, in use, against the seal face 24. The seal ring 26 and stem 16 together form a dynamic seal, in that the faces 24 and 28 are urged together by fluid pressure within the valve body 10.
To ensure adequate contact under low internal pressure conditions, a preload urging the faces 24 and 28 together is provided by a preload spring 30 engaged between the valve body 10 and a lock nut 32 secured to the top of the stem 16.
<Desc/Clms Page number 4>
The primary metal seal system 20 also includes a static metal seal 34. The seal 34 is a metal"C" seal of known type and engages between the seal ring 26 and the valve body 10; the seal 34 is held between angles on these elements to allow the small degree of movement required to ensure full contact with the stem under all operating conditions.
The valve stem 16 is guided and supported in the valve body 10 by means of upper and lower bushes 36.
This ensures the reliability and longevity of the sealing system, and also minimises the valve operating torque.
In this embodiment, a resilient lip seal 38 of known type is also provided above the metal sealing system 20. The resilient lip seal-38 could be dispensed with, but acts as a back up system and would normally be required by specifiers.
In the illustrated embodiment, the seal surface 24 is formed on the flange 22 which is integral with the valve stem 16. As an alternative (not illustrated), the seal surface could be formed on a separate member such as a ring secured to or seated in the valve stem.
Other modifications and improvements may be made to the foregoing embodiment within the scope of the present invention.
Claims (10)
- CLAIMS 1. A sealing system for a rotary valve stem comprising a first seal member located on the valve stem and providing an annular, upwardly facing seal face of hardened metal, a second seal member located on the valve body and providing an annular, downwardly facing seal face of hardened metal, the first and second seal members being located such that said seal faces are in abutment, and at least one of said seal members being arranged to be urged by fluid pressure within the valve body towards the other seal member.
- 2. A sealing system according to claim 1 wherein the first seal member comprises an annular flange formed on or secured to the valve stem, and the second seal member comprises a ring seated in a recess in the valve body.
- 3. A sealing system according to claim 2 wherein a static metal seal is located between the ring and the valve body.
- 4. A sealing system according to claim 3 wherein the static metal seal is a metal"C"seal.
- 5. A sealing system according to any preceding claim wherein the seal faces are preloaded together.
- 6. A sealing system according to claim 5 wherein the seal faces are preloaded together by spring<Desc/Clms Page number 6>means acting between the valve stem and the valve body.
- 7. A sealing system according to any preceding claim wherein one or more bushes are provided between the valve stem and the valve body for rotational guidance and support of the valve stem.
- 8. A sealing system according to claim 7 wherein a secondary seal is located between a pair of said bushes.
- 9. A sealing system according to claim 8 wherein the secondary seal is a resilient lip seal.
- 10. A sealing system substantially as hereinbefore described with reference to the accompanying drawing.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0127299A GB0127299D0 (en) | 2001-11-14 | 2001-11-14 | Sealing system for valve stem |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB0226562D0 GB0226562D0 (en) | 2002-12-18 |
| GB2384286A true GB2384286A (en) | 2003-07-23 |
Family
ID=9925743
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0127299A Ceased GB0127299D0 (en) | 2001-11-14 | 2001-11-14 | Sealing system for valve stem |
| GB0226562A Withdrawn GB2384286A (en) | 2001-11-14 | 2002-11-14 | Sealing system for valve stem |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0127299A Ceased GB0127299D0 (en) | 2001-11-14 | 2001-11-14 | Sealing system for valve stem |
Country Status (1)
| Country | Link |
|---|---|
| GB (2) | GB0127299D0 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103672015A (en) * | 2013-11-30 | 2014-03-26 | 无锡智能自控工程股份有限公司 | Balanced metal valve seat sealing structure for high-temperature high-pressure regulating ball valve |
| EP3037697A1 (en) * | 2013-08-28 | 2016-06-29 | Kitz Corporation | High-pressure trunnion ball valve and hydrogen station using same |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3458172A (en) * | 1966-05-26 | 1969-07-29 | Dresser Ind | Ball valve |
| US3636972A (en) * | 1970-05-07 | 1972-01-25 | Domer Scaramucci | Jacketed valve |
| DE2419129A1 (en) * | 1974-04-20 | 1975-11-06 | Boehmer Gmbh Maschf W | Valve with metallic spherical closure - has metallic sealing rings in contact with hardened spherical closure unit |
| US4332370A (en) * | 1979-08-10 | 1982-06-01 | Serck Industries, Limited | Fluid flow control valve, principally of the ball or plug type |
| US4935313A (en) * | 1985-02-12 | 1990-06-19 | Masco Corporation Of Indiana | Process of manufacturing seal members having a low friction coefficient |
| EP0401443A1 (en) * | 1989-05-16 | 1990-12-12 | Taco, Inc. | Low torque ball valve |
| US4983355A (en) * | 1986-12-03 | 1991-01-08 | Masco Corporation Of Indiana | Seal element of hard material sintered from a semi-finished form with organic binder |
-
2001
- 2001-11-14 GB GB0127299A patent/GB0127299D0/en not_active Ceased
-
2002
- 2002-11-14 GB GB0226562A patent/GB2384286A/en not_active Withdrawn
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3458172A (en) * | 1966-05-26 | 1969-07-29 | Dresser Ind | Ball valve |
| US3636972A (en) * | 1970-05-07 | 1972-01-25 | Domer Scaramucci | Jacketed valve |
| DE2419129A1 (en) * | 1974-04-20 | 1975-11-06 | Boehmer Gmbh Maschf W | Valve with metallic spherical closure - has metallic sealing rings in contact with hardened spherical closure unit |
| US4332370A (en) * | 1979-08-10 | 1982-06-01 | Serck Industries, Limited | Fluid flow control valve, principally of the ball or plug type |
| US4935313A (en) * | 1985-02-12 | 1990-06-19 | Masco Corporation Of Indiana | Process of manufacturing seal members having a low friction coefficient |
| US4983355A (en) * | 1986-12-03 | 1991-01-08 | Masco Corporation Of Indiana | Seal element of hard material sintered from a semi-finished form with organic binder |
| EP0401443A1 (en) * | 1989-05-16 | 1990-12-12 | Taco, Inc. | Low torque ball valve |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3037697A1 (en) * | 2013-08-28 | 2016-06-29 | Kitz Corporation | High-pressure trunnion ball valve and hydrogen station using same |
| EP3037697A4 (en) * | 2013-08-28 | 2017-05-10 | Kitz Corporation | High-pressure trunnion ball valve and hydrogen station using same |
| CN103672015A (en) * | 2013-11-30 | 2014-03-26 | 无锡智能自控工程股份有限公司 | Balanced metal valve seat sealing structure for high-temperature high-pressure regulating ball valve |
Also Published As
| Publication number | Publication date |
|---|---|
| GB0226562D0 (en) | 2002-12-18 |
| GB0127299D0 (en) | 2002-01-02 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |