GB2038451A - Sealing of valves - Google Patents

Sealing of valves Download PDF

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Publication number
GB2038451A
GB2038451A GB7940784A GB7940784A GB2038451A GB 2038451 A GB2038451 A GB 2038451A GB 7940784 A GB7940784 A GB 7940784A GB 7940784 A GB7940784 A GB 7940784A GB 2038451 A GB2038451 A GB 2038451A
Authority
GB
United Kingdom
Prior art keywords
valve
closure member
valve seat
sealing
seat
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.)
Granted
Application number
GB7940784A
Other versions
GB2038451B (en
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Wartsila Oy AB
Original Assignee
Wartsila Oy AB
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Wartsila Oy AB filed Critical Wartsila Oy AB
Publication of GB2038451A publication Critical patent/GB2038451A/en
Application granted granted Critical
Publication of GB2038451B publication Critical patent/GB2038451B/en
Expired legal-status Critical Current

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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
    • 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
    • F16K1/32—Details
    • F16K1/34—Cutting-off parts, e.g. valve members, seats
    • 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
    • F16K1/32—Details
    • F16K1/34—Cutting-off parts, e.g. valve members, seats
    • F16K1/36—Valve members
    • F16K1/38—Valve members of conical shape
    • F16K1/385—Valve members of conical shape contacting in the closed position, over a substantial axial length, a seat surface having the same inclination

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Lift Valve (AREA)

Abstract

In a method of sealing a valve of the kind comprising a closure member 1 movable into engagement with a seat 6, the closure member 1 having an element 5 with a sealing surface inclined relative to the direction of movement of the closure member 1, at least the sealing surface of the closure member 1 is made of a material that is so much harder than the material of the valve seat 6 that the normal closing power of the valve is able to create plastic deformation of the valve seat 6 by means of the closure member 1. As a result, the valve seat 6 is deformed in accordance with the form of the sealing surface of the closure member 1. <IMAGE>

Description

SPECIFICATION Sealing of valves This invention relates to a method of sealing a valve of the kind comprising a valve closure member movable into engagement with a valve seat, the valve closure member having a sealing surface which is inclined relative to the direction of movement of the valve closure member.
In known sealing arrangements of valves of the kind referred to, the surface of the valve seat is usually of harder material than the valve closure member. Since the seat surface usually has a sharp edge, it causes depressions and grooves in the softer valve closure member when closing the valve. Hence, the valve is not quite tight, unless said grooves always have exactly the same position.This requires a guidance without clearance of the valve closure member, which is impossible to achieve in practice, so that the valve may, as a consequence, leak after it has been operated only a few times.
Attempts have been made to avoid wear of the sealing surfaces of a valve by using equally hard materials in the valve seat and in the valve closure member. In practice, however, wear is impossible to avoid, due to which a valve will start leaking after a certain period of use according to the wear of the seat surface.
The present invention aims to improve the tightness of a valve of the kind referred to, so that it will maintain its tightness for a considerably longer time than in known arrangements.
According to the invention a method of sealing a valve of the kind referred to is characterised in that at least the sealing surface of the valve closure member is made of a harder material than the valve seat, and that by making use of the ordinary closing power of the valve, plastic, i.e.
permanent, deformations are created in the valve seat by means of the valve closure member, so that the valve seat is deformed in accordance with the sealing surface of the valve closure member. In this way, when the position of the valve closure member varies on the occasion of each closing of the valve, the valve seat is deformed against the harder valve closure member and in spite of the wearing process the valve remains tight.
Additionally, the tightness is improved because the valve seat, i.e. the portion which undergoes the greater deformation, is immovable.
That portion of the valve closure member which includes the sealing surface can with advantage be made of a separate ring-shaped element. The sealing portion of the valve closure member and the valve seat can be made of tempered steel of different qualities, a steel quality of greater hardness being selected for the valve closure member than for the valve seat. Stellites of various qualities may also be used, a harder stellite being selected for the valve closure member than for the valve seat. In order to avoid penetration into the sealing surfaces of the valve by any substantial amount of solid particles which may be present in the fluid flowing through the valve, a material having a greater hardness than the hardness of said particles is selected for the valve seat.In this case, it is preferred that the hardness of the sealing surface of the valve closure member exceeds the hardness of the valve seat by at least 1 0 per cent The invention also relates to a sealing arrangement of a valve of the kind referred to, the sealing arrangement being characterised in that at least the sealing surface of the valve closure member is made of a harder material than the valve seat, and in that by making use of the ordinary closing power of the valve, the valve closure member is arranged to create plastic, i.e.
permanent, deformations in the value seat, so that the valve seat is deformed in accordance with the sealing surface of the valve closure member. The sealing portion of the valve closure member can with advantage be a separate ring-shaped element.
The invention will now be described, by way of example, with reference to the accompanying drawing, the single Figure of which is an axial sectional view of an embodiment of a valve sealing arrangement according to the invention.
The valve shown partly in the Figure comprises a housing 4 in which there is a valve closure member 1 having a spindle 2 movable through a valve cover 3. The valve closure member 1 has a separate ring-shaped element 5 which includes the sealing surface of the closure member, and the housing 4 is provided with a valve seat 6.
According to the invention the element 5 is made of a harder material than valve seat 6, so that, when closing the valve, the valve seat 6 is deformed against the harder element 5 of the valve closure member and the valve remains tight in spite of the wear.
The invention can be applied with advantage not only to valves with frusto-conical valve closure members, as shown in the drawing, but also to valves with ball-shaped valve closure members.
The materials of the valve seat and the closure member should be selected according to the operational purpose of the valve. The material of the valve seat should, of course, not be too highly elastic. It must have the quality of being at least slightly deformable by plastic deformation.
1. A method of sealing a valve of the kind comprising a valve closure member movable into engagement with a valve seat, the valve closure member having a sealing surface which is inclined relative to the direction of movement of the valve closure member, characterised in that at least the sealing surface of the valve closure member is made of a harder material than the valve seat, and that by making use of the ordinary closing power of the valve, plastic, i.e. permanent, deformations are created in the valve seat by means of the valve closure member, so that the valve seat is deformed in accordance with the sealing surface of the valve closure member.
2. A method as claimed in claim 1 in which the
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (9)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Sealing of valves This invention relates to a method of sealing a valve of the kind comprising a valve closure member movable into engagement with a valve seat, the valve closure member having a sealing surface which is inclined relative to the direction of movement of the valve closure member. In known sealing arrangements of valves of the kind referred to, the surface of the valve seat is usually of harder material than the valve closure member. Since the seat surface usually has a sharp edge, it causes depressions and grooves in the softer valve closure member when closing the valve. Hence, the valve is not quite tight, unless said grooves always have exactly the same position.This requires a guidance without clearance of the valve closure member, which is impossible to achieve in practice, so that the valve may, as a consequence, leak after it has been operated only a few times. Attempts have been made to avoid wear of the sealing surfaces of a valve by using equally hard materials in the valve seat and in the valve closure member. In practice, however, wear is impossible to avoid, due to which a valve will start leaking after a certain period of use according to the wear of the seat surface. The present invention aims to improve the tightness of a valve of the kind referred to, so that it will maintain its tightness for a considerably longer time than in known arrangements. According to the invention a method of sealing a valve of the kind referred to is characterised in that at least the sealing surface of the valve closure member is made of a harder material than the valve seat, and that by making use of the ordinary closing power of the valve, plastic, i.e. permanent, deformations are created in the valve seat by means of the valve closure member, so that the valve seat is deformed in accordance with the sealing surface of the valve closure member. In this way, when the position of the valve closure member varies on the occasion of each closing of the valve, the valve seat is deformed against the harder valve closure member and in spite of the wearing process the valve remains tight. Additionally, the tightness is improved because the valve seat, i.e. the portion which undergoes the greater deformation, is immovable. That portion of the valve closure member which includes the sealing surface can with advantage be made of a separate ring-shaped element. The sealing portion of the valve closure member and the valve seat can be made of tempered steel of different qualities, a steel quality of greater hardness being selected for the valve closure member than for the valve seat. Stellites of various qualities may also be used, a harder stellite being selected for the valve closure member than for the valve seat. In order to avoid penetration into the sealing surfaces of the valve by any substantial amount of solid particles which may be present in the fluid flowing through the valve, a material having a greater hardness than the hardness of said particles is selected for the valve seat.In this case, it is preferred that the hardness of the sealing surface of the valve closure member exceeds the hardness of the valve seat by at least 1 0 per cent The invention also relates to a sealing arrangement of a valve of the kind referred to, the sealing arrangement being characterised in that at least the sealing surface of the valve closure member is made of a harder material than the valve seat, and in that by making use of the ordinary closing power of the valve, the valve closure member is arranged to create plastic, i.e. permanent, deformations in the value seat, so that the valve seat is deformed in accordance with the sealing surface of the valve closure member. The sealing portion of the valve closure member can with advantage be a separate ring-shaped element. The invention will now be described, by way of example, with reference to the accompanying drawing, the single Figure of which is an axial sectional view of an embodiment of a valve sealing arrangement according to the invention. The valve shown partly in the Figure comprises a housing 4 in which there is a valve closure member 1 having a spindle 2 movable through a valve cover 3. The valve closure member 1 has a separate ring-shaped element 5 which includes the sealing surface of the closure member, and the housing 4 is provided with a valve seat 6. According to the invention the element 5 is made of a harder material than valve seat 6, so that, when closing the valve, the valve seat 6 is deformed against the harder element 5 of the valve closure member and the valve remains tight in spite of the wear. The invention can be applied with advantage not only to valves with frusto-conical valve closure members, as shown in the drawing, but also to valves with ball-shaped valve closure members. The materials of the valve seat and the closure member should be selected according to the operational purpose of the valve. The material of the valve seat should, of course, not be too highly elastic. It must have the quality of being at least slightly deformable by plastic deformation. CLAIMS
1. A method of sealing a valve of the kind comprising a valve closure member movable into engagement with a valve seat, the valve closure member having a sealing surface which is inclined relative to the direction of movement of the valve closure member, characterised in that at least the sealing surface of the valve closure member is made of a harder material than the valve seat, and that by making use of the ordinary closing power of the valve, plastic, i.e. permanent, deformations are created in the valve seat by means of the valve closure member, so that the valve seat is deformed in accordance with the sealing surface of the valve closure member.
2. A method as claimed in claim 1 in which the sealing portion of the closure member comprising the sealing surface is made of a separate ringshaped element.
3. A method as claimed in claim 1 or 2, in which the sealing portions of the closure member and the valve seat are made of tempered steel of different qualities, a steel quality of greater hardness being selected for the valve closure member.
4. A method as claimed in claims t or 2, in which the sealing portions of the closure member and the valve seat are made of stellite of different qualities, a harder stellite quality being selected for the valve closure member.
5. A method as claimed in any of the preceding claims, in which a material is selected for the valve seat which has a hardness which is greater that the hardness of solid particles present in the fluid flowing through the valve.
6. A method as claimed in claim 5, in which the hardness of the sealing surface of the closure member exceeds the hardness of the valve seat by at least 10percent.
7. A valve sealing arrangement for a valve of the kind comprising a valve closure member movable into engagement with a valve seat, the valve closure member having a sealing surface which is inclined relative to the direction of movement of the valve closure member, characterised in that at least the sealing surface of the valve closure member is made of a harder material than the valve seat, and in that by making use of the ordinary closing power of the valve, the valve closure member is arranged to create plastic, i.e. permanent, deformations in the valve seat, so that the valve seat is deformed in accordance with the sealing surface of the valve closure member.
8. A valve sealing arrangement as claimed in claim 7, in which the sealing portion of-the closure member s a separate ring-shaped element.
9. A valve constructed and arranged substantially as herein described with reference to, and as illustrated in, the accompanying drawing.
GB7940784A 1978-11-27 1979-11-26 Sealing of valves Expired GB2038451B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FI783611A FI68889C (en) 1978-11-27 1978-11-27 SAETESVENTIL

Publications (2)

Publication Number Publication Date
GB2038451A true GB2038451A (en) 1980-07-23
GB2038451B GB2038451B (en) 1983-05-05

Family

ID=8512180

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7940784A Expired GB2038451B (en) 1978-11-27 1979-11-26 Sealing of valves

Country Status (6)

Country Link
JP (1) JPS5576259A (en)
DE (1) DE2947588A1 (en)
FI (1) FI68889C (en)
FR (1) FR2442387B1 (en)
GB (1) GB2038451B (en)
SE (1) SE438541B (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4671322A (en) * 1985-08-19 1987-06-09 Halliburton Company Sequential formation tester having three way normally closed valve
US4722508A (en) * 1984-10-31 1988-02-02 Rosenmund Ag Valve on processing plant
US5100100A (en) * 1990-09-12 1992-03-31 Mks Instruments, Inc. Fluid control and shut off valve
EP1128109A1 (en) * 2000-02-22 2001-08-29 Siemens Building Technologies AG Valve for control device

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FI68890C (en) * 1981-02-06 1985-11-11 Waertsilae Oy Ab TAETNING AV SAETESVENTIL
DE19530224B4 (en) * 1995-08-17 2006-01-05 Friatec Ag Sealing arrangement for a butterfly valve or a butterfly valve
JP5727347B2 (en) * 2011-10-18 2015-06-03 太平洋工業株式会社 Flow control valve

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE891953C (en) * 1953-08-20 Siemens-Schuckertwerke Aktiengesellschaft, Berlin Und Erlangen Arrangement for sealing mutually movable parts made of ceramic materials, especially in the case of valves. Eat. 10
US1979910A (en) * 1930-10-20 1934-11-06 Super Diesel Tractor Corp Valve
GB370451A (en) * 1931-01-08 1932-04-08 Johann Zagorski Improvements in or relating to fluid-tight valves especially for high pressures and temperatures
FR1011946A (en) * 1950-05-06 1952-07-01 Spray jet fire extinguisher air pump
FR1249395A (en) * 1959-11-14 1960-12-30 Centre Nat Rech Scient Very high vacuum valve
DE1186712B (en) * 1960-09-15 1965-02-04 Akad Wissenschaften Ddr Valve
DE1190756B (en) * 1961-12-28 1965-04-08 Akad Wissenschaften Ddr Valve
US3450385A (en) * 1966-12-12 1969-06-17 Rockwell Mfg Co Grooved valve disc
US3767164A (en) * 1971-07-01 1973-10-23 Milwaukee Valve Co Inc Throttle-shutoff valve

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4722508A (en) * 1984-10-31 1988-02-02 Rosenmund Ag Valve on processing plant
US4671322A (en) * 1985-08-19 1987-06-09 Halliburton Company Sequential formation tester having three way normally closed valve
US5100100A (en) * 1990-09-12 1992-03-31 Mks Instruments, Inc. Fluid control and shut off valve
EP1128109A1 (en) * 2000-02-22 2001-08-29 Siemens Building Technologies AG Valve for control device

Also Published As

Publication number Publication date
SE438541B (en) 1985-04-22
FR2442387B1 (en) 1985-11-22
FI68889C (en) 1985-11-11
JPS5576259A (en) 1980-06-09
FI68889B (en) 1985-07-31
FI783611A (en) 1980-05-28
DE2947588A1 (en) 1980-10-16
GB2038451B (en) 1983-05-05
SE7909682L (en) 1980-05-28
FR2442387A1 (en) 1980-06-20

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Legal Events

Date Code Title Description
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
PCNP Patent ceased through non-payment of renewal fee

Effective date: 19931126