US3722540A - Sectional control valves - Google Patents
Sectional control valves Download PDFInfo
- Publication number
- US3722540A US3722540A US3722540DA US3722540A US 3722540 A US3722540 A US 3722540A US 3722540D A US3722540D A US 3722540DA US 3722540 A US3722540 A US 3722540A
- Authority
- US
- United States
- Prior art keywords
- sections
- pressure passages
- passages
- high pressure
- low pressure
- 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 - Lifetime
Links
Images
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
- F16K27/00—Construction of housing; Use of materials therefor
- F16K27/04—Construction of housing; Use of materials therefor of sliding valves
- F16K27/041—Construction of housing; Use of materials therefor of sliding valves cylindrical slide valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B13/00—Details of servomotor systems ; Valves for servomotor systems
-
- 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
- F16K11/00—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves
- F16K11/10—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with two or more closure members not moving as a unit
- F16K11/20—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with two or more closure members not moving as a unit operated by separate actuating members
- F16K11/22—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with two or more closure members not moving as a unit operated by separate actuating members with an actuating member for each valve, e.g. interconnected to form multiple-way valves
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T137/00—Fluid handling
- Y10T137/8593—Systems
- Y10T137/87169—Supply and exhaust
Definitions
- ABSTRACT A sectional control valve is provided made up of a plurality of control sections between an inlet manifold and an outlet manifold, the sections having interconnecting high pressure passages and low pressure passages which connect with one another at the junction of the sections, each control section having service passages means for connecting a fluid motor and a movable valve element to control communication of its service passage means with its high and low pressure passages, said sections having substantially flat mating surfaces at their junctions, a relief groove extending lengthwise of this section through at least one of said flat mating surfaces parallel to the movable element and intersecting the low pressure passages, said high pressure passages intersecting the flat mating surfaces spaced from said relief groove and continuous low pressure seal means surrounding the low and high pressure passages and intersecting the relief groove adjacent its ends.
- This invention relates to sectional control valves and particularly to sectional valve interface sealing systems.
- Sectional control valves are generally well known in the art. They generally consist of an inlet manifold and an outlet manifold with a plurality of control sections therebetween. Fluid under pressure is delivered to the inlet manifold, passed through the control sections and collected in the exhaust or outlet manifold and returned to a tank. It is obvious that in order to pass the fluid through the several control valves from inlet manifold to outlet manifold it is necessary for the several sections to have interconnecting passages, at least some of which carry high pressure fluid and others carry low pressure fluid.
- This type of sectional control valve has many recognized advantages, but at the same time suffer from the problem of leakage of fluid at the joints between sections which fluid escapes to the exterior of the valve mechanism. This is undesirable because it is not only wasteful of hydraulic fluid but provides a wet, oily surface upon which dirt accumulates as unsightly accretions on the apparatus.
- the present invention provides a system for sealing the mating surfaces of these valve sections so as to prevent fluid leakage to the valve exterior and to recover any fluid which leaks from the passages into the area between sections.
- a sectional control valve made up of a plurality of control sections between an inlet manifold and an outlet manifold, said sections having interconnecting high pressure passages and low pressure passages which connect with one another at the junction of the sections, each control section having service passage means for connecting a fluid motor and a movable valve element to control communication of its service passage means with its high pressure and low pressure passages, said sections each having substantially flat mating surfaces at their junctions, a relief groove extending lengthwise of the section through at least one of said flat mating surfaces parallel to the movable element and intersecting the low pressure passages, said high pressure passage intersecting the flat mating surfaces spaced from said relief groove, and means surrounding the low and high pressure passages and intersecting the relief groove adjacent each of its ends defining a low pressure seal.
- the movable valve element operates in a longitudinal bore in the section which bore intersects all low and high pressure passages.
- the movable valve element is preferably hollow at each end and solid in the middle providing two spaced apart axial cavities with spaced passages communicating through the valve element wall adjacent each end.
- the low pressure seal is preferably a continuous rubber strand in a shallow groove in the mating surfaces. Any fluid which escapes the high pressure passages is directed into their low pressure passages by means of the seal and longitudinal groove.
- FIG. 1 is a top plan view of a sectional control valve
- FIG. 2 is a cross-sectional view of a valve control section embodying our invention
- FIG. 3 is a side elevational view of a mating surface of a control section according to our invention.
- FIG. 4 is an end elevational view of the control section of FIG. 2 taken on the line IV--IV of FIG. 3;
- FIG. 5 is a section on the line V-V of FIG. 3.
- asectional control valve embodying this invention including an inlet manifold 10, an outlet manifold 11 and a plurality of intermediate control sections 12.
- a plurality of bolts 13 pass through both manifolds and the control sections to hold all the sections tightly clamped together.
- the control sections 12 are of the closed center type arranged to provide parallel circuit operation.
- the control section shown in FIG. 3 is of the double acting type. It is provided with a longitudinal bore with a valve element 21 slidable axially therein from a neutral position to one of two working positions.
- the valve element 21 is provided with a hollow axial cavity 22 and 23 at each end communicating through the valve element wall at spaced points by passages 22a and 22b and 23a and 23b respectively.
- the valve element is adapted to connect one of the two parallel high pressure chambers 24 and 25 with one of the two motor ports 26 and 27 which are adapted to be connected to a hydraulic motor such as a cylinder or the like while connecting the other motor port with one of the two exhaust chambers 28 and 29.
- a relief groove 30 is milled lengthwise of at least one of the mating or joining faces 31 and 32 of the control sections.
- the relief groove 30 extends parallel to the core 20 and intersects the exhaust chambers 28 and 29.
- High pressure passages 34 and 35 extend angularly from the high pressure chambers 24 and 25 to the machined mating or joining faces 31 and 32 terminating in ports 36 and 37 spaced from the relief groove 30.
- a continuous rubber O-ring type of low pressure seal 38 is inserted in a holding groove 39 which surrounds the area of the joining faces 31 and 32 carrying the ports 36 and 37 and openings of the exhaust chambers into the relief groove.
- This construction provides a number of advantages. It eliminates the troublesome leakage with the resultant undesirable accumulation of dirt and dust and it eliminates the problem of binding the movable valve member in the valve bore which occurred in prior art valves because of the distortion of the valve body by the escaped high pressure fluid trapped between adjacent valve sections. With the present construction, the relief groove 30 drains away the high pressure fluid from the area paralleling the bore so that no pressure can build up in this area.
- a sectional control valve comprising an inlet manifold, an outlet manifold, a plurality of control sections between said inlet and outlet manifolds, said sections having interconnecting high pressure passages and two interconnecting low pressure passages at opposite ends of the sections which connect with one another at the junction of the sections, each control section having service passage means for connecting a fluid motor and a movable valve element to control communication of its service passage means with its high and low pressure passages, said sections having substantially flat mating surface at their junctions, a relief groove extending lengthwise of the section through at least one of said fiat mating surfaces parallel to the movable valve element and intersecting the low pressure passages, said high pressure passages intersecting the flat mating surfaces spaced from said relief groove and resilient low pressure seal means surrounding the low and high pressure passages and intersecting the relief groove adjacent each of its ends.
- valve element is hollow at each end and solid in the middle to provide two spaced apart axial cavities with spaced passages, communicating through the valve element wall adjacent each end.
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Valve Housings (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
A sectional control valve is provided made up of a plurality of control sections between an inlet manifold and an outlet manifold, the sections having interconnecting high pressure passages and low pressure passages which connect with one another at the junction of the sections, each control section having service passages means for connecting a fluid motor and a movable valve element to control communication of its service passage means with its high and low pressure passages, said sections having substantially flat mating surfaces at their junctions, a relief groove extending lengthwise of this section through at least one of said flat mating surfaces parallel to the movable element and intersecting the low pressure passages, said high pressure passages intersecting the flat mating surfaces spaced from said relief groove and continuous low pressure seal means surrounding the low and high pressure passages and intersecting the relief groove adjacent its ends.
Description
United States Patent [1 1 Mazur et al.
I SECTIONAL CONTROL VALVES [75] Inventors: Joseph N. Mazur, Poland; Edward J. Ratkay, Canfield; Robert F. Hodgson, Mahoning, all of Ohio [73] Assignee: Commercial Shearing & Stamping Company, Youngstown, Ohio [22] Filed: May 20, 1971 [21] App]. No.: 145,219
[56] References Cited UNITED STATES PATENTS 3,133,559 5/1964 Tennis ..137/596 3,481,364 2/1969 Hodgson et al ..l37/596 3,324,885 6/1967 Beech ....25 l/367 X Primary ExaminerHenry T. Klinksiek Assistant Examiner-Robert J. Miller Att0rneyBuell, Blenko 8L Ziesenheim [4 1 Mar. 27, 1973 [57] ABSTRACT A sectional control valve is provided made up of a plurality of control sections between an inlet manifold and an outlet manifold, the sections having interconnecting high pressure passages and low pressure passages which connect with one another at the junction of the sections, each control section having service passages means for connecting a fluid motor and a movable valve element to control communication of its service passage means with its high and low pressure passages, said sections having substantially flat mating surfaces at their junctions, a relief groove extending lengthwise of this section through at least one of said flat mating surfaces parallel to the movable element and intersecting the low pressure passages, said high pressure passages intersecting the flat mating surfaces spaced from said relief groove and continuous low pressure seal means surrounding the low and high pressure passages and intersecting the relief groove adjacent its ends.
5 Claims, 5 Drawing Figures PATENTEDNARZTIBYS 37 2540 III II! ill III I I A 0000B Fig .5. 38"] Q Q INVENTORS Joseph N. Mozur,
Edward J. Rotkoy 8 Robert F. Hodqson SECTIONAL CONTROL VALVES This invention relates to sectional control valves and particularly to sectional valve interface sealing systems.
Sectional control valves are generally well known in the art. They generally consist of an inlet manifold and an outlet manifold with a plurality of control sections therebetween. Fluid under pressure is delivered to the inlet manifold, passed through the control sections and collected in the exhaust or outlet manifold and returned to a tank. It is obvious that in order to pass the fluid through the several control valves from inlet manifold to outlet manifold it is necessary for the several sections to have interconnecting passages, at least some of which carry high pressure fluid and others carry low pressure fluid.
This type of sectional control valve has many recognized advantages, but at the same time suffer from the problem of leakage of fluid at the joints between sections which fluid escapes to the exterior of the valve mechanism. This is undesirable because it is not only wasteful of hydraulic fluid but provides a wet, oily surface upon which dirt accumulates as unsightly accretions on the apparatus.
The present invention provides a system for sealing the mating surfaces of these valve sections so as to prevent fluid leakage to the valve exterior and to recover any fluid which leaks from the passages into the area between sections.
Preferably we provide a sectional control valve made up of a plurality of control sections between an inlet manifold and an outlet manifold, said sections having interconnecting high pressure passages and low pressure passages which connect with one another at the junction of the sections, each control section having service passage means for connecting a fluid motor and a movable valve element to control communication of its service passage means with its high pressure and low pressure passages, said sections each having substantially flat mating surfaces at their junctions, a relief groove extending lengthwise of the section through at least one of said flat mating surfaces parallel to the movable element and intersecting the low pressure passages, said high pressure passage intersecting the flat mating surfaces spaced from said relief groove, and means surrounding the low and high pressure passages and intersecting the relief groove adjacent each of its ends defining a low pressure seal. Preferably the movable valve element operates in a longitudinal bore in the section which bore intersects all low and high pressure passages. The movable valve element is preferably hollow at each end and solid in the middle providing two spaced apart axial cavities with spaced passages communicating through the valve element wall adjacent each end. The low pressure seal is preferably a continuous rubber strand in a shallow groove in the mating surfaces. Any fluid which escapes the high pressure passages is directed into their low pressure passages by means of the seal and longitudinal groove.
In the foregoing general description of our invention we have set out certain objects, purposes and advantages of our invention. Other objects, purposes and advantages of this invention will be apparent from a consideration of the following description and the accompanying drawings, in which:
FIG. 1 is a top plan view of a sectional control valve;
FIG. 2 is a cross-sectional view of a valve control section embodying our invention,
FIG. 3 is a side elevational view of a mating surface of a control section according to our invention;
FIG. 4 is an end elevational view of the control section of FIG. 2 taken on the line IV--IV of FIG. 3; and
FIG. 5 is a section on the line V-V of FIG. 3.
Referring to the drawings, we have illustrated asectional control valve embodying this invention including an inlet manifold 10, an outlet manifold 11 and a plurality of intermediate control sections 12. A plurality of bolts 13 pass through both manifolds and the control sections to hold all the sections tightly clamped together.
The control sections 12 are of the closed center type arranged to provide parallel circuit operation. The control section shown in FIG. 3 is of the double acting type. It is provided with a longitudinal bore with a valve element 21 slidable axially therein from a neutral position to one of two working positions. The valve element 21 is provided with a hollow axial cavity 22 and 23 at each end communicating through the valve element wall at spaced points by passages 22a and 22b and 23a and 23b respectively. In the two operating positions the valve element is adapted to connect one of the two parallel high pressure chambers 24 and 25 with one of the two motor ports 26 and 27 which are adapted to be connected to a hydraulic motor such as a cylinder or the like while connecting the other motor port with one of the two exhaust chambers 28 and 29. A relief groove 30 is milled lengthwise of at least one of the mating or joining faces 31 and 32 of the control sections. The relief groove 30 extends parallel to the core 20 and intersects the exhaust chambers 28 and 29. High pressure passages 34 and 35 extend angularly from the high pressure chambers 24 and 25 to the machined mating or joining faces 31 and 32 terminating in ports 36 and 37 spaced from the relief groove 30. A continuous rubber O-ring type of low pressure seal 38 is inserted in a holding groove 39 which surrounds the area of the joining faces 31 and 32 carrying the ports 36 and 37 and openings of the exhaust chambers into the relief groove.
With the foregoing construction it will be evident that any high pressure fluid which escapes from the high pressure passages 34 and 35 will be directed to the relief groove 30 and will then enter one of the exhaust chambers where it will be returned to the tank.
This construction provides a number of advantages. It eliminates the troublesome leakage with the resultant undesirable accumulation of dirt and dust and it eliminates the problem of binding the movable valve member in the valve bore which occurred in prior art valves because of the distortion of the valve body by the escaped high pressure fluid trapped between adjacent valve sections. With the present construction, the relief groove 30 drains away the high pressure fluid from the area paralleling the bore so that no pressure can build up in this area.
While we have shown a preferred embodiment and practice of our invention in the foregoing specification, it will be understood that this invention may be otherwise embodied within the scope of the following claims.
We claim:
l. A sectional control valve comprising an inlet manifold, an outlet manifold, a plurality of control sections between said inlet and outlet manifolds, said sections having interconnecting high pressure passages and two interconnecting low pressure passages at opposite ends of the sections which connect with one another at the junction of the sections, each control section having service passage means for connecting a fluid motor and a movable valve element to control communication of its service passage means with its high and low pressure passages, said sections having substantially flat mating surface at their junctions, a relief groove extending lengthwise of the section through at least one of said fiat mating surfaces parallel to the movable valve element and intersecting the low pressure passages, said high pressure passages intersecting the flat mating surfaces spaced from said relief groove and resilient low pressure seal means surrounding the low and high pressure passages and intersecting the relief groove adjacent each of its ends.
2. A sectional control valve as claimed in claim 1 wherein the movable valve element operates in a longitudinal bore in the section, which bore intersects all low and high pressure passages.
3. A sectional control valve as claimed in claim 1 wherein the valve element is hollow at each end and solid in the middle to provide two spaced apart axial cavities with spaced passages, communicating through the valve element wall adjacent each end.
4. A sectional control valve as claimed in claim 1 wherein the low pressure seal means is a continuous rubber ring in a shallow groove in at least one of the mating surfaces of each said sections.
5. A sectional control valve as claimed in claim 1 wherein the high pressure passages extend angularly from the bore to the mating surfaces.
Claims (5)
1. A sectional control valve comprising an inlet manifold, an outlet manifold, a plurality of control sections between said inlet and outlet manifolds, said sections having interconnecting high pressure passages and two interconnecting low pressure passages at opposite ends of the sections which connect with one another at the junction of the sections, each control section having service passage means for connecting a fluid motor and a movable valve element to control communication of its service passage means with its high and low pressure passages, said sections having substantially flat mating surface at their junctions, a relief groove extending lengthwise of the section through at least one of said flat mating surfaces parallel to the movable valve element and intersecting the low pressure passages, said high pressure passages intersecting the flat mating surfaces spaced from said relief groove and resilient low pressure seal means surrounding the low and high pressure passages and intersecting the relief groove adjacent each of its ends.
2. A sectional control valve as claimed in claim 1 wherein the movable valve element operates in a longitudinal bore in the section, which bore intersects all low and high pressure passages.
3. A sectional control valve as claimed in claim 1 wherein the valve element is hollow at each end and solid in the middle to provide two spaced apart axial cavities with spaced passages, communicating through the valve element wall adjacent each end.
4. A sectional control valve as claimed in claim 1 wherein the low pressure seal means is a continuous rubber ring in a shallow groove in at least one of the mating surfaces of each said sections.
5. A sectional control valve as claimed in claim 1 wherein the high pressure passages extend angularly from the bore to the mating surfaces.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14521971A | 1971-05-20 | 1971-05-20 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3722540A true US3722540A (en) | 1973-03-27 |
Family
ID=22512118
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US3722540D Expired - Lifetime US3722540A (en) | 1971-05-20 | 1971-05-20 | Sectional control valves |
Country Status (9)
Country | Link |
---|---|
US (1) | US3722540A (en) |
JP (1) | JPS52167628U (en) |
AU (1) | AU463931B2 (en) |
BR (1) | BR7107424D0 (en) |
CA (1) | CA948962A (en) |
DE (1) | DE2141162B2 (en) |
FR (1) | FR2138595B1 (en) |
GB (1) | GB1337369A (en) |
ZA (1) | ZA715523B (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4430927A (en) * | 1980-06-19 | 1984-02-14 | Rubery Owen (Hydraulics) Limited | Hydraulic valves |
US20130146158A1 (en) * | 2010-08-23 | 2013-06-13 | Kosmek Ltd. | Directional control valve device |
WO2015168369A1 (en) * | 2014-04-30 | 2015-11-05 | Parker-Hannifin Corporation | Hydraulic sectional control valve with multiple relief slots |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2575156Y2 (en) * | 1991-11-12 | 1998-06-25 | 株式会社小松製作所 | Pressure oil supply device |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR1353251A (en) * | 1962-03-30 | 1964-02-21 | Hydraulic Unit Specialities Co | Sectional control valve and similar devices with improved seals |
NL292328A (en) * | 1962-05-03 | 1900-01-01 |
-
1971
- 1971-05-20 US US3722540D patent/US3722540A/en not_active Expired - Lifetime
- 1971-08-17 DE DE19712141162 patent/DE2141162B2/en not_active Withdrawn
- 1971-08-18 ZA ZA715523A patent/ZA715523B/en unknown
- 1971-10-05 CA CA124,497A patent/CA948962A/en not_active Expired
- 1971-10-08 AU AU34379/71A patent/AU463931B2/en not_active Expired
- 1971-11-08 BR BR742471A patent/BR7107424D0/en unknown
- 1971-11-22 FR FR7141762A patent/FR2138595B1/fr not_active Expired
-
1972
- 1972-02-25 GB GB881072A patent/GB1337369A/en not_active Expired
-
1977
- 1977-06-13 JP JP7608577U patent/JPS52167628U/ja active Pending
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4430927A (en) * | 1980-06-19 | 1984-02-14 | Rubery Owen (Hydraulics) Limited | Hydraulic valves |
US20130146158A1 (en) * | 2010-08-23 | 2013-06-13 | Kosmek Ltd. | Directional control valve device |
US9115728B2 (en) * | 2010-08-23 | 2015-08-25 | Kosmek Ltd. | Directional control valve device |
WO2015168369A1 (en) * | 2014-04-30 | 2015-11-05 | Parker-Hannifin Corporation | Hydraulic sectional control valve with multiple relief slots |
US9683586B2 (en) | 2014-04-30 | 2017-06-20 | Parker-Hannifin Corporation | Hydraulic sectional control valve with multiple relief slots |
Also Published As
Publication number | Publication date |
---|---|
BR7107424D0 (en) | 1973-07-17 |
CA948962A (en) | 1974-06-11 |
FR2138595A1 (en) | 1973-01-05 |
DE2141162A1 (en) | 1972-11-23 |
AU463931B2 (en) | 1975-08-07 |
JPS52167628U (en) | 1977-12-19 |
AU3437971A (en) | 1973-04-12 |
GB1337369A (en) | 1973-11-14 |
FR2138595B1 (en) | 1975-08-29 |
ZA715523B (en) | 1972-04-26 |
DE2141162B2 (en) | 1972-11-23 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0767330B1 (en) | Manifold-type solenoid valves | |
US3654960A (en) | Modular hydraulic system | |
US3338257A (en) | Double check valve | |
EP1580438A2 (en) | Hydraulic valve section with reduced bore distortion | |
US2807280A (en) | Program control valve | |
US3561489A (en) | Hydraulically or pneumatically controllable slide valve arrangement | |
US3133559A (en) | Sectional control valves | |
US2637303A (en) | Hydraulic actuated valve | |
US3722540A (en) | Sectional control valves | |
US5911243A (en) | Multiport conversion system for butterfly valve | |
CN210317969U (en) | High-low pressure switching valve | |
CN109764018B (en) | Multi-way valve with unloading and oil return logic functions in working piece | |
US3406989A (en) | Combined multiple fluid distribution panel blocks and connector means therefor | |
US3158164A (en) | Multiple block fluid distribution panel for mounting fluid control devices and method of directing fluid flow through the blocks | |
CA2741502A1 (en) | Valve assembly | |
CA2137070A1 (en) | Valve Construction | |
JPH0444881Y2 (en) | ||
EP0200182A3 (en) | Piston-type hydraulic control valve | |
CN209838811U (en) | Multi-way valve with unloading and oil return logic functions in working piece | |
US4159024A (en) | Fluid control valve | |
US3707162A (en) | Logic control valve | |
JP2571089Y2 (en) | Switching valve | |
US4448215A (en) | Multiple flow control valve | |
DE3315056C2 (en) | Electro-hydraulic multi-way control valve | |
CN218063470U (en) | Strong corrosion-resistant monoblock hydraulic valve of leakproofness |