US2562837A - Hydraulic pumping jack - Google Patents

Hydraulic pumping jack Download PDF

Info

Publication number
US2562837A
US2562837A US625502A US62550245A US2562837A US 2562837 A US2562837 A US 2562837A US 625502 A US625502 A US 625502A US 62550245 A US62550245 A US 62550245A US 2562837 A US2562837 A US 2562837A
Authority
US
United States
Prior art keywords
valve
line
tank
pressure
jack
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
Application number
US625502A
Inventor
White Ira Morgan
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.)
PELTON WATER WHEEL Co
Original Assignee
PELTON WATER WHEEL CO
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 PELTON WATER WHEEL CO filed Critical PELTON WATER WHEEL CO
Priority to US625502A priority Critical patent/US2562837A/en
Application granted granted Critical
Publication of US2562837A publication Critical patent/US2562837A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04BPOSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B47/00Pumps or pumping installations specially adapted for raising fluids from great depths, e.g. well pumps
    • YGENERAL 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
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S417/00Pumps
    • Y10S417/904Well pump driven by fluid motor mounted above ground

Description

July 31, 1951 wHn-E 2,562,837
HYDRAULIC PUMPING JACK Fiied Oct. 50, 1945 3 SheetsSheet l 4:. 7 g /9 INVENTOR.
IRA MORGAN WH/ TE @zwqzw ATTORNEYS July 31, 1951 1, M, w E 2,562,837
HYDRAULIC PUMPING JACK INVENTOR. 1E4 MORGAN WHITE ATTORNE Y5 July 31, 1951 l. M. WHITE 2,562,837
HYDRAULIC PUMPING JACK Filed Oct. 50, 1945 3 Sheets-Sheet 3 v INVENTOR. [RA MORGAN WHITE Y 242-. wkzm ak ATTORNEYS Patented July 31, 1951 HYDRAULIC PUIVIPING JACK Ira Morgan White, Oakland, Calif., assignor to The Pelton Water Wheel Company, San Francisco, Calii'., a corporation of California Application October 30, 1945, Serial N 0. 625,502
6 Claims. (Cl. 60-52 This invention relates in general to a hydraulic deep well pumping jack system including a hydraulic jack; a balancing pressure tank, a constant displacement pump and an automatic control valve. The balancing pressure tank of the system is maintained at a pressure such that the resulting lifting force of the pressure applied in the hydraulic jack would be equal to the rod weight plus one-half of the fluid weight normally lifted by the jack. The operating pump and control valve are disposed between the jack and the balancing tank so that operation of the pump and control valve to produce flow from the tank to the jack will lift the piston in the jacket while operation of the pump and control valve to produce flow from the jack to the tank will lower the piston in the jack. A special hydraulic control mechanism is provided to reverse automatically the action as the jack reaches the terminal point of each end of the stroke. By maintaining the pressure in the balancing tank as described above, the pump is subjected to a substantially constant load during the upstroke and downstroke of the ack. During the upstroke the pump must develop suflicient pressure which when applied to the jack will augment the balancing tank pressure and lift the entire rod plus the fluid load. Conversely, during the downstroke, the pump must sufficiently reduce the pressure within the jack so as to remove fluid from the jack so that the load on the jack will be reduced to the rod load only.
In addition to the normal operating devices required for the hydraulic pumping jack, the jack is provided with a safety feature in order to bring about shutdown of the jack in the event of rod breakage and consequent loss of load to the jack. If such a device were not provided, the pump would be subjected to excessive overdrive conditions in the event of loss of part of the load supported by the jack. For example, a rod breakage during the upstroke of the jack could reduce the load on the pump discharge to below the pump suction supplied by the balancing tank. This condition could possibly set about destructive forces if the rod breakage control device were not incorporated.
In general then, the object of this invention is the provision in a hydraulic pumping jack system of the character described, of means for protecting the system from damage by reason of abnormal operating conditions, such as sucker rod breakage.
More specifically, the object of this invention is the provision in a hydraulic pumping jack system of the character described, of a normally open valve which will automatically close in response to predetermined sub-normal pressure in the jack.
The invention possesses other advantageous.
features, some of which with the foregoing will be set forth at length in the following description where that form of the invention, which has been selected for illustration in the drawings accompanying and forming a part of the present specification, is outlined in full. In said drawings, one form of the invention is shown, but it is to be understood that it is not limited tosuch form, since the invention, as set forth in the claims, may be embodied in a plurality of forms.
Referring to the drawings:
Fig. 1 diagrammatically illustrates a hydraulic pumping jack system embodying the objects of my invention shown with the system in the upstroke portion of its cycle.
Fig. 2 is a view similar to Fig. 1 but showing the system in the downstroke portion .of its cycle.
Fig. 3 is an enlarged detail longitudinal section of the automatic valve incorporated in the system to safeguard it due to any damage which might otherwise occur as a result of any abnormal differential pressures to which the system might be subjected.
In general, the system shown in these figures includes a hydraulic jack A, the piston of which carries a polished rod; a balanced pressure tank B, maintained at a pressure sufficient to produce a lifting load in the jack equal to the rod load plus one-half of the fluid load supported by the jack; a constant displacement pump C, capable of producing a pressure above the tank pressure sufficient to lift the rod weight plus the fluid weight, and also capable of reducing the pressure in the jack below the pressure tank so as to permit the sucker rod to drop; a control valve D, disposed between the pump and the balanced pressure tank for alternately delivering fluid from the pressure tank to the hydraulic jack on the upstroke of the jack and then from the jack to the tank on the downstroke of the jack; a pilot valve E, responsive differentially and hydraulically to the terminal movements of the hydraulic -jack piston for operating the main control valve; and a shutoff valve F, for closing the circuit between the balanced-pressure tank and the main control valve in response to any predetermined abnormal differential pressure existing in the system.
associated with the cylinders ll and 3!.
As disclosed in Figs. 1 and 2, the hydraulic jack A includes a cylinder I, with which is operatively associated a piston 2. Depending from the piston I through a suitable stuiflng box in the lower end of the cylinder I, is a polished rod 8, to which is fastened the sucker rod of an oil well pump. The cylinder I is provided on its lower end with a fluid operating medium inlet and outlet port 4 and at its upper end with a fluid outlet port I communicating through a check valve I, line I and check valve I with an intake port provided in the lower end of the cylinder above the port I. Also provided on the upper end of the cylinder l are a pair of longitudinally spaced outlet drainage ports II and I2, communicating (through line ll, cheekvalve ll, line ll. scaven in pump It, line ll, check valve It and line II) with an intake port II provided in the lower end of the balancing pressure tank B.
The pump C is of the constant displacement type, including a pair of opposed suction chambers I2 and 23 and a discharge compartment 24, and is adapted to be driven by any suitable power means. The suction chambers 22 and II are provided respectively with inlet ports 26 and II and the discharge compartment with a discharge outlet 11 and with a relief valve outlet 2| communicating through a relief valve 2! with an inlet port II associated with the suction chamber 23.
The main control valve D is of the piston type including a main cylinder 32 provided with five longitudinally spaced annular channels II, a, II, It and 31. Provided on either end of the valve D, coaxially with the main cylinder 32, are smaller cylinders It and It. operatively associated with the main cylinder 32 are a pair of longitudinally spaced pistons ll and 42 mounted on a piston shaft ll, and carried on the ends of the shaft 41 arepistons M and I! operatively The simultaneous movement of the pistons ll, 42, 44 and I! from their positions as shown in Fig. 1 to the positions shown in Fig. 2 is effected through the pilot valve E in a manner which will be described later in connection with the description of the valve E. Communication between the lower end of the balanced pressure tank B and the annular channel It is established through the normally open port It of the shutoff valve 1''. Fluid from the balanced pressure tank B flows through the valvefF, line 4'l and port a into the annular channel it. From this channel the fluid passes into the channel 31, through a port 31a associated with the channel 31 and through a line I and the inlet port 2' into the suction chamber 23. The line It communicates through a line ll with a line II which, in turn. communicates with the inlet port of the suction chamber 22 and with a port "a associated with the annular chamber I3. It will, therefore, be seen that the fluid passing through the channels ll and II of the main control valve will be delivered to both of the suction chambers 22 and 23 of the pump C. The pump C then delivers this fluid through its outlet port 21, through a line 52 and a port 350 associated with the channel into the channel 35. From the channel II. the fluid passes through the channel 34, through a port a associated with this channel and through a line 53 and the port 4, into the lower end of the cylinder I. In this position the pump C operates to pass fluid from the tank B through the main control valve D into the lower end of the cylinder i, thereby to raise the piston}.
past the piston 2 is delivered through ports H' and i2, line It, check valve l4, line ll, scavenging pump IO, line ll, check valve II, and line ll through the port 2| associated with the lower end of the tank B into the tank B. In this connection. it should be noted that the scavenging pump it is operated so as to maintain substantially atmospheric pressure on the check valve ll.
When the piston 2 rises above the port I. fluid under the main pump pressure passes through port I, check valve 6, the upper portion of the line I, and line 84 to the left end port ll associated with the pilot valve E.
a The pilot valve E is of the same type as the main control valve D, including a main cylinder 56 with which are operatively associated three longitudinally spaced coaxial pistons II. II and SI, fastened to a common shaft II. Formed on the right end of the pilot valve E is a cylinder I of a smaller diameter than the main cylinder II and which is provided with an outlet port I. operatively associated with the cylinder n is a piston t4, fastened to and forming a continuation of the right end of the shaft I. Communication between the port a and the port 30b associated with the channel ll of the main control valve D, is established by a line I. With the main valve in the position as shown in Pig. 1, fluid from the tank B is delivered from the channel it through the line 6' to the small cylinder it. However, since the area of the piston N is less than the area of the piston 51. the pump discharge fluid pressure in line ll will cause pistons I1, I, II and N to move to the right to assume the position shown in Fig. 2.
With the pilot valve E in the position as shown in Fig. 2, and the main control valve in the position as shown in Fig. 1, fluid under tank pres sure passes upwardly through line 41, port 30b, line 60, valve E and line 01 into the left end cylinder ll of the main valve D to force the pistons ll. 42, 44 and II to the right, as shown in Fig. 2. Due to the right hand movement of the piston I, fluid contained in its cylinder ll passes through line '8, pilot valve E, line 0!, line H, to the drainline I, from'which the pressure is increased by the scavenging pump ll suflicient to replace the fluid in the bottom of the tank B through the check valve ll.
With main valve D, as well as pilot valve I, in the positions as shown in Fig. 2, the pump C operates to draw liquid from the lower end of the hydraulic Jack cylinder i, through port 4, upwardly through line II, through the intercommunicating ports a and Ila of the main control valve D, and into the suction chambers 22 and II of the pump. The pump then operates to deliver this fluid from its discharge compartment 24 through the intercommunicating ports lie and "a of the main control valve D, line 41 and the normally open port 48 of the shutoif valve 1''. back into the balancing tank B.
When the piston 2 of the hydraulic jack passes the check valve 6 on its downward stroke. no effect is produced on pilot valve E because check valve 8 does not permit the flow of fluid back into the cylinder I. When, however, the piston 2 passes port Q'on its downward stroke, pilot valve E is placed in communication (through line I, check valve 8, cylinder l, line ll, check valve ll, scavenging pump II and check valve ll) with the lower end of the tank B. Concurrently, the right hand end of small piston 64 of the pilot valve is subjected to tank pressure through the intercommunicating ports 35a and 39b of the main control valve D and through the line 65. Since at this point in the cycle of operation the left end of the piston 51 is only under the influence of substantially atmospheric pressure, the pump pressure on the piston 64 moves it to the left, whereby the pilot valve E assumes its original position as shown in Fig. 1. In this latter position of the system, fluid under tank pressure passes (through line 41, the intercommunicating ports 39a and 36b of the main valve, line 66, the intercommunicating ports I2 and 13 of the pilot valve and line 68) to the right end cylinder 39 of the main valve. Since the left end piston 44 of this valve is now in communication with the drain system (through line 61, the intercommunicating ports 14 and 15 of the pilot valve, line 99 and line 1|) the tank pressure on the piston 45 results in moving this piston and its associated pistons to theleft to assume their original position as shown in Fig. 1. The system so far described is in condition to repeat the complete cycle of operation as above disclosed.
As already stated, the static load on the polished rod 3 may at times be as high as or greater than 20,000 pounds and, therefore, when due to a breakage in the sucker rod any appreciable portion of this load is lost, the main pump would of course be subjected to an excessive overdrive condition on the upstroke. To safeguard the pump and its associated mechanism against such a contingency, the shutoff valve F is inserted in the line between the tank B and the main valve D, with its main port 46 normally open. The shutoff valve F, as best shown in Fig. 3, comprises a generally S-shaped casing 9|, provided at either end with flanged ports 46 and 92, the port 45 being connected with the lower end of tank B and the port 82 with line 41, as shown in Figs. 1 and 2. Formed on one side of the cas ing BI is a cylinder 83, the left end of which is closed by a cap 84, forming an internal flange 84a having an internal diameter somewhat less than the diameter of the cylinder 83. The cylinder 83 is provided at its right end with a port 95 communicating with lines 69 and II, and the left end of the cylinder is connected through a port 86 formed in the cap 84 to a pipe 8! connecting with line 53. In pipe 81 is inserted a three-way valve 88, all as shown in Figs. 1 and 2. Extending through the right end of the cylinder 83 is a piston rod 89, and secured to the left end of this red is a piston 9| operatively disposed within cylinder 83. Fastened to the right end of the rod 89 is a valve closure member 92 adapted to seal against a seat 93, formed in the outer end of port 46.
The stem 89 is so proportioned with respect to the piston 9| that under normal conditions of operation, the force applied on the head end of the piston 9| is greater than the combined pressures acting on the rod end of the piston 9| and the tank pressure acting on the valve member 92, especially on the rod portion 89 thereof, the resultant force being such as to hold the piston Si in the extreme right position. Consequently, the valve 92 remains in the open position. If, however, the sucker rod attached to the polished rod 3 breaks and the polished rod is relieved of a portion of its load, there will be a correspond ing decrease in the pressure within the jack cylinder Under these abnormal conditions, the reduced pressure under the jack piston and effective upon the head end of the piston 9| is overcome by the pressure in the balancing tank B acting first upon the rod 99 and, as the valve 92 moves toward closed position and reduces the pressure in the passage around the stem 89, acting finally upon the tank side of the valve 92. This is suflicient to close the shut on valve F during the abnormal upstroke of the jack, and
thereby prevent the further passage of fiuid from the tank B to the control and pilot valves D and E and to the main pump C. The shutoff valve F will remain closed until the pressures on either side of its closure member 92 have been substantially equalized. In the event of breakage in the sucker rod, this can only be done by dismantling and repairing the deep well pumping equipment.
The valve F can also be closed by turning the three-way valve 98 so that the left end of the cylinder 83 is placed in communication through the valve 88 with the line ll of the drain system, thereby to reduce the pressure on the left end of the piston 9| substantially to atmospheric pressure. In this connection, the valve F is provided with an auxiliary normally closed by-pass valve 93 disposed in a line 94 connected between the two sides of the closure member 92. To open the shutoff valve F, the three-way valve 89 is turned to its normal position in communication with the jack cylinder and the by-pass valve 93 is turned to its open position so as to equalize the pressure on both sides of the closure memher 92. The shutoff valve F will then open, making it possible to put the jack A into operation by starting the pump C.
As a further safety measure, the pump C is provided'with a relief valve 29 across its suction and discharge sides to protect the system in the event of any blockage therein.
I claim:
1. A hydraulic pumping jack system comprising: a hydraulic jack cylinder; a piston therein; a balancing pressure tank; a line between said jack cylinder and said tank; a pump disposed in said line; valve means responsive to the operation of said piston for periodically reversing the connections of said pump so as to cause a flow of fluid from said tank to said cylinder on the upstroke of said piston and then from the cylinder to the tank on the downstroke of said piston; a shutoff valve interposed in said line between said tank and said pump; and means responsive to a predetermined pressure difference between said hydraulic Jack cylinder and said tank for closing said shutoff valve.
2. A hydraulic pumping jack system comprising: a hydraulic jack cylinder; a piston therein; a balancing pressure tank; a control valve; a line connecting said control valve to said cylinder and to said tank; a'pump connected to said control valve, said control valve being effective periodically to reverse the connections of said pump with said line so that fluid from the tank is pumped to the jack cylinder on the upstroke of said piston and on the downstroke of said piston 'fiuid from the jack cylinder is pumped to the tank; a shutoff valve disposed in the line between .said tank and said control valve; and means responsive to pressure in said line between said hydraulic jack cylinder and said control valve and to pressure in said line between said tank and said control valve for operating said shutoff valve.
3. A hydraulic pumping jack'system compris ing: a hydraulic jack cylinder; a piston therein; a balancing pressure tank; a pump; a line between said jack cylinder and said tank; a control asoassv valve ior connecting alternately the low pressure side of said pump with said tank and the high pressure side of said pump with said jack cylinder on the upstroke of said piston and then the low pressure side of the pump with the jack cylinder and the high pressure side of the pump with the tank on the downstroke of said piston; means for actuating said control valve in response to the operation of said piston; a shutoff valve disposed in the line between the tank and the pump; means responsive to a predetermined pressure difierence between said tank and said hydraulic jack cylinder for closing said shutoil' valve; and a relief valve interposed between the low pressure and high pressure sides of said pump.
4. A hydraulic pumping jack system comprismg: a hydraulic jack cylinder; a piston therein; a balancing pressure tank; a pump having an inlet and an outlet; valve means responsive to the operation of said piston for controlling fiow between said pump, said cylinder, and said tank; conduits connecting said pump inlet and outlet to said valve means; a first line interconnecting said cylinder and said valve means; a second line interconnecting said tank and said valve means; a shutol! valve in said second line; a differential pressure-responsive member for operating said shut-oi! valve; means for exposing one side of said pressure-responsive member to pressure in said first line; and means for exposing the other side of said pressure-responsive member to pressure in said second line.
5. A hydraulic pumping jack system comprising: a hydraulic jack cylinder; a piston therein; a balancing pressure tank; a pump having an inlet and an outlet; valve means responsive to the operation of said piston for controlling fiow between said pump, said cylinder, and said tank; conduits connecting said pump inlet and outlet to said valve means; a first line interconnecting said cylinder and said valve means; a second line interconnecting said tank and said valve means; a shut-oil. valve in said second line; a pressureresponsive member having a large diameter portion, an intermediate portion, and a small diameter portion for operating said shutoi! valve; means for subjecting said intermediate portion to substantially atmospheric pressure; means for subjecting said large diameter portion to pressure in said first line; and means for subjecting said small diameter portion to pressure in said second line.
6. A hydraulic pumping jack system comprising: a hydraulic jack cylinder; a piston movable therein; a balancing pressure tank; a line between said cylinder and said tank; a pump having an inlet and an outlet; a valve responsive to the position of said piston in said cylinder for connecting said pump outlet to said cylinder and said pump inlet to said tank and vice versa; means responsive to a first pressure and to a second pressure for controlling flow in said line between said tank and said pump; and means for subjecting said controlling means to pressure between said tank and said pump as a first pressure and to pressure between said cylinder and said pump as a second pressure.
IRA MORGAN WHITE.
REFERENCES CITED The following references are of record in the file oi! this patent:
UNITED s'rs'rns PATENTS Number Name Date 1,290,722 Doble Jan. 7, 1919 1,842,961 Coppus Jan. 26, 1932 1,988,164 Cummins Jan. 15, 1935 2,277,761 Hubbard Mar. 31, 1942 2,325,138 Kyle July 27, 1943 2,470,253 Kyle May 17, 1949
US625502A 1945-10-30 1945-10-30 Hydraulic pumping jack Expired - Lifetime US2562837A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US625502A US2562837A (en) 1945-10-30 1945-10-30 Hydraulic pumping jack

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US625502A US2562837A (en) 1945-10-30 1945-10-30 Hydraulic pumping jack

Publications (1)

Publication Number Publication Date
US2562837A true US2562837A (en) 1951-07-31

Family

ID=24506388

Family Applications (1)

Application Number Title Priority Date Filing Date
US625502A Expired - Lifetime US2562837A (en) 1945-10-30 1945-10-30 Hydraulic pumping jack

Country Status (1)

Country Link
US (1) US2562837A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2651914A (en) * 1950-02-28 1953-09-15 Joy Mfg Co Pumping head and operating mechanism for wells
US2665550A (en) * 1949-02-25 1954-01-12 United States Steel Corp Fluid pressure actuated pumping unit
US2838910A (en) * 1955-08-18 1958-06-17 Baldwin Lima Hamilton Corp Hydraulic pumping jack

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1290722A (en) * 1913-12-27 1919-01-07 Pelton Water Wheel Co Water-conduit and valve therefor.
US1842961A (en) * 1925-11-16 1932-01-26 Anna M C Wechsberg Locomotive feed water heater
US1988164A (en) * 1931-05-23 1935-01-15 Oil Engine Dev Company Pump mechanism
US2277761A (en) * 1939-01-20 1942-03-31 Hydraulic Pumper Inc Hydraulic pumping apparatus
US2325138A (en) * 1940-04-09 1943-07-27 Pelton Water Wheel Co Hydraulic pumping jack
US2470252A (en) * 1945-11-09 1949-05-17 Pelton Water Wheel Co Hydraulic pumping jack with control responsive to abnormal conditions

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1290722A (en) * 1913-12-27 1919-01-07 Pelton Water Wheel Co Water-conduit and valve therefor.
US1842961A (en) * 1925-11-16 1932-01-26 Anna M C Wechsberg Locomotive feed water heater
US1988164A (en) * 1931-05-23 1935-01-15 Oil Engine Dev Company Pump mechanism
US2277761A (en) * 1939-01-20 1942-03-31 Hydraulic Pumper Inc Hydraulic pumping apparatus
US2325138A (en) * 1940-04-09 1943-07-27 Pelton Water Wheel Co Hydraulic pumping jack
US2470252A (en) * 1945-11-09 1949-05-17 Pelton Water Wheel Co Hydraulic pumping jack with control responsive to abnormal conditions

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2665550A (en) * 1949-02-25 1954-01-12 United States Steel Corp Fluid pressure actuated pumping unit
US2651914A (en) * 1950-02-28 1953-09-15 Joy Mfg Co Pumping head and operating mechanism for wells
US2838910A (en) * 1955-08-18 1958-06-17 Baldwin Lima Hamilton Corp Hydraulic pumping jack

Similar Documents

Publication Publication Date Title
US2927429A (en) Reversible hydraulic door operator system
US2267380A (en) Hold-down system
US2595307A (en) Portable well servicing rig
US570727A (en) Valve mechanism
US2238063A (en) Fluid pressure system and valve mechanism therefor
US2342301A (en) Gas lift valve
US3212406A (en) Pumping systems
US2345531A (en) Hydraulic actuating mechanism
US1955154A (en) Valve mechanism
US2197320A (en) Electric control valve
US2338903A (en) Fluid operated pump assembly
US2873762A (en) Control valve for fluid pressure operated mechanisms
US2562615A (en) Hydraulic control system responsive to pressure and flow rate
US3049101A (en) Hydraulic mechanism
US1964196A (en) Regulator for hydraulic cylinders
US2588520A (en) Hydraulically operated check valve mechanism
US2994335A (en) Flow valve devices
SE7909030L (en) DEVICE FOR CONNECTING A PRESSURE FLUID CELL TO A CONSUMER
US3092135A (en) Full opening safety valve for pipe strings
US4353286A (en) Hydraulic control system with a pipeline antiburst safety device for a double acting drive cylinder
CN101171429B (en) Self-synchronizing hydraulic system
US1934758A (en) Automatic valve
US2438285A (en) Telescopic hydraulic jack
US2890683A (en) Fluid actuated control valve means for fluid motors
US2269189A (en) Fluid pump