Valve actuator and pilot assembly therefor

• US 4,187,870 A
• Filed: 08/03/1078
• Issued: 02/12/1980
• Est. Priority Date: 05/06/1977
• Status: Expired due to Term

• Current Assignee: Baker International Corporation (Baker Hughes Company)
• Original Assignee: Baker International Corporation (Baker Hughes Company)
• Inventors: Akkerman, Neil H.
• Primary Examiner(s): Schwadron, Martin P.
• Assistant Examiner(s): Walton, G. L.
• Application Number:
  US05/930,462
• Time in Patent Office: 329,276 Days
• Field of Search: 137/102, 137/458, 137/459, 137/460, 137/461, 137/488, 251/28, 251/63, 251/63.5, 251/63.6, 251/318, 251/326
• US Class Current: 137/102
• CPC Class Codes: F16K 17/10 with auxiliary valve for fluid operation of the main valve
• CPC Class Codes: F16K 31/36 in which fluid from the circuit is constantly supplied to the fluid motor
• CPC Class Codes: F16K 43/00 Auxiliary closure means in valves, which in case of repair, e.g. rewashering, of the valve, can take over the function of the normal closure means; Devices for temporary replacement of parts of valves for the same purpose
• CPC Class Codes: Y10T 137/2544 Supply and exhaust type
• CPC Class Codes: Y10T 137/7725 Responsive to both high and low pressure or velocity
• CPC Class Codes: Y10T 137/7762 Fluid pressure type

Abstract

A valve actuator and a pilot assembly which may be utilized either alone or with the actuator is responsive to control fluid pressure for moving an operative means of a valve between open and closed positions. The actuator has a housing defining a cylindrical bore therethrough and a shaft is carried in the housing which is engageable with the operative means. A piston is carried by one of the shaft and the housing and is sealingly slidable along the other of the shaft and the housing and is longitudinally movable within the cylindrical bore.

The pilot assembly comprises a cylindrical housing having pilot means within the housing, the pilot means having valve seat means thereon. Normally free traveling spherical members are provided immediate the pilot means and define valve head means selectively sealingly engageable on the pilot means to open and close the pilot means to control fluid flow therethrough. A pilot spool within the housing and immediate the pilot means and operably associatable with the pilot means and the spherical members permits selective movement of the spherical members to the immediate vicinity of the valve seat means of the pilot means. The spool is manipulatable in at least one of linear and rotary directions. Fluid flow causes the spherical members to seek and selectively seal onto the valve seat means. The spool is selectively shiftable in response to variation of fluid pressure to permit the fluid pressure to act within the actuator to manipulate the operative means between open and closed positions. A stem extension is provided within the actuator housing and is engaged to the spool, together with resisting means, such as compressible springs and the like, within the housing and are carried around the stem for resisting travel of the spool in one direction. Differential pressure areas are defined across the spool and are responsive to fluid pressure variance to selectively overcome travel resistance of the spool by the resistance means and to thereafter shift the spool.

Claims

1. A flow line valve actuator respondable to a source of fluid pressure for moving an operative means of a valve between open and closed position, comprising:

a housing defining a bore therethrough;

a shaft carried in said housing and engagable with said operative means;

piston means carried by one of said shaft and said housing and sealingly slidable along the other of said shaft and said housing and longitudinally movable within said cylindrical bore;

first and second fluid chamber means companionly associated with said piston means yielding a differential force across said piston means upon increase of fluid pressure within one of said chamber means, said shaft being selectively shiftable longitudinally in a first direction to move said operative means to one of open and closed position by increase in fluid pressure within one of said first and second fluid chamber means, said shaft being selectively shiftable longitudinally in a second direction to move said operative means to the other of said open and closed position upon subsequent decrease in fluid pressure in one of said first and second chamber means and upon increase of fluid pressure within the other of said first and second chamber means;

pilot means within said housing having valve seat means thereon;

normally free traveling spherical members immediate said pilot means defining valve head means and selectively sealingly engagable on said pilot means to open and close said pilot means to control fluid flow therethrough; and

pilot spool means within said housing immediate said pilot means and operably associatable with said pilot means and said spherical members to permit selective engagement of said spherical members onto said valve seat means of said pilot means, said spool means being selectively shiftable in one of linear and rotational directions within said housing immediate said valve head and seat means and not constrained against the other of linear and rotational directions to permit said fluid pressure to act within said actuator to manipulate said operative means between open and closed position upon only one of linear and rotational shifting of said spool means, the selective engagement of said head and seat means being sealingly insensitive to the other of linear and rotational shifting of said spool means.

2. The flow line valve actuator of claim 1 wherein said pilot means is carried on said shaft and within said housing.

3. The flow line valve actuator of claim 1 wherein said spool means is selectively shiftable in response to variation of said fluid pressure.

4. The actuator of claim 1 additionally comprising:

stem extension means within said housing and engaged to said spool means; and

means within said housing and carried around said stem extension means for resisting travel of said spool means in a first direction.

5. The actuator of claim 1 additionally comprising:

stem extension means within said housing and engaged to said spool means; and

means comprising at least one compressible spring element within said housing and carried around said stem extension means for resisting travel of said spool means in a longitudinal direction.

6. The actuator of claim 1 additionally comprising:

stem extension means within said housing and engaged to said spool means; and

means comprising at least one compressible spring element within said housing and carried around said stem extension means for resisting travel of said spool means in an upward direction.

7. The actuator of claim 1 additionally comprising:

stem extension means within said housing and engaged to said spool means;

means within said housing and carried around said stem extension means for resisting travel of said spool means in a first direction; and

differential area means across said spool means responsive to differential pressure to selectively overcome travel resistance of said spool means by said resisting means and to shift said spool means in a second direction.

8. The actuator of claim 1 additionally comprising:

stem extension means within said housing and engaged to said spool;

means comprising at least one compressible spring element within said housing and carried around said stem extension means for resisting travel of said spool means in a first direction; and

differential area means across said spool means responsive to differential pressure to selectively overcome travel resistance of said spool means by said resisting means and to shift said spool means in a downward direction.

9. The actuator of claim 1 additionally comprising check valve means shiftable in a first direction to permit transmission of fluid pressure from said source therethrough in a first direction and sealingly engageable within said passageway member in response to transmission of fluid pressure in a second direction to prevent transmission of said fluid pressure from said source therethrough in a first direction, said check valve means having pressure relief means therein for transmission of fluid pressure therethrough in said second direction while said check valve means is sealingly engaged within said flow passageway member.

10. The flow line valve actuator of claim 1 additionally comprising compensating piston means within said shaft and responsive to at least one of increase and decrease of said source of fluid pressure for operation of said pilot means to manipulate said operative means between open and closed position.

11. The flow line valve actuator of claim 1 additionally comprising static seal means on said shaft and sealingly engagable within said housing to isolate a source of fluid pressure from within said actuator.

12. The flow line actuator of claim 1 further comprising supply valve means for selective communication of said source of fluid pressure within said actuator and bleed valve means within said actuator for venting of fluid pressure within said actuator.

13. The flow line valve actuator of claim 12 additionally comprising check valve means in association with said supply valve means, said check valve means being manipulatable to closed position upon removal of said supply valve means from said actuator housing to isolate said source of control pressure from within said actuator housing thereabove.

14. The flow line valve actuator of claim 12 wherein at least one of said supply and bleed valve means comprises a valve seal set assembly therefor selectively removable from within said actuator housing.

15. The flow line valve actuator of claim 1 wherein said pilot means is reciprocably carried on and selectively disengagable from said piston means.

16. The flow line valve actuator of claim 1 wherein said shaft is automatically shiftable longitudinally in a first to move said operative means to closed position by decrease of said source of fluid pressure within one of said first and second fluid chamber means.

17. A flow line valve actuator respondable to a source of fluid pressure for moving an operative means of a valve between open and closed position, comprising:

a housing defining a bore therethrough, a shaft carried in said housing and engagable with said operative means;

piston means carried by one of said shaft and said housing and sealingly slidable along the other of said shaft and said housing and longitudinally movable within said cylindrical bore;

first and second fluid chamber means companionly associated with said piston means yielding a differential force across said piston means upon increase of fluid pressure within one of said chamber means, said shaft being selectively shiftable longitudinally in a first direction to move said operatively means to one of open and closed position and selectively shiftable longitudinally in a second direction to move said operative means to the other of said open and closed position upon pressure equalization across said piston means;

pilot means within said housing having valve seat means thereon;

normally free traveling spherical members immediate said pilot means defining valve head means and selectively sealingly engagable upon said pilot means to open and close said pilot means to control fluid flow therethrough; and

pilot spool means within said housing immediate said pilot means and operably associatable with said pilot means and said spherical members to permit selective engagement of said spherical members onto said valve seat means of said pilot means, said spool means being selectively shiftable in response to variation of said fluid pressure in one of linear and rotational directions within said housing immediate said valve head and seat means and not constrained against the other of linear and rotational directions to permit said fluid pressure to act within said actuator to manipulate said operative means between open and closed position upon only one of linear and rotational shifting of said spool means, the selective engagement of said head and seat means being sealingly insensitive to the other of linear and rotational shifting of said spool means.