The tank port T of the holding valve 20 is connected through a line 23 to the tank 11. However, a hollow poppet housing 37 is retained within the chamber 36. The line 18 connects the fourth port of the four-way valve 15 to the valve port V of the counterbalance valve 20. In counterbalance valves, a differential area that controls the relief function is fixed by the manufacturer upon fabricating the cage and poppet and is subject to wide tolerances when diameters of the valve components are large. 6. Select your pilot ratio. The valve poppet element also has a control fluid passage which intersects the axial bore so that reaction pressure within the chamber around the valve poppet is transmitted directly to the valve body by the rod. This is likely to be about 30% of the load induced pressure but check the valve manufacturer recommendations. This invention allows the relief setting and operation to be controlled accurately and reliably in a counterbalance or "holding" valve. At this point, the counterbalance valve shuts abruptly and the cylinder stops. Turn adjustment clockwise to decrease setting and release load. Exemplary of such machines are man baskets, cranes and backhoes. The pilot pressure controls the amount of poppet opening against the bias of spring 39 during normal operation as in a standard counterbalance valve. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT. 5. © 2004-2021 FreePatentsOnline.com. They are designed to create backpressure at the return line of the actuator to prevent losing control over the load. The valve should be set at least 1.3 times the maximum expected load-induced pressure at port 1. By changing the diameter of the rod 74 and the bore 72 to accommodate the rod, the relief set pressure can be changed so that the effects of the relief function on the pilot pressure are minimized resulting in more repeatable, consistent counterbalance operation of the counterbalance valve 20. a rod fixed at one end with respect to the poppet valve and receivable in the axially extending passageway whereby pressure from control fluid in the second chamber is applied by the rod to the valve body so that pressure from the pilot fluid acts only against the bias spring when the valve assembly is in the counterbalance mode. It is basically the counterbalance valve and the compensator interacting with each other. They are frequently employed to ‘counterbalance' a load as … The two-stage valve has overcome many instability problems by preventing the total decay of the stored energy in the cylinder and stopping the valve overreacting. An extended allen-key wrench may be needed because the strong springs in the valve make them difficult to adjust under pressure. Lastly, by preventing fluid within both the cylinder chambers from escaping therefrom, the piston can be locked in a predetermined position within the cylinder. Screw the valve into a … 1; and. Referring now to the drawings, there is illustrated in FIG. Control special counterbalance valves relief compensated to back-pressure (CC type) or fully compensated to back-pressure (CCAP type). In its third position, the four-way valve prevents fluid within both of the chambers from escaping therefrom, causing the piston to be locked in a predetermined position. a poppet valve cage received with the body, the poppet valve cage having a chamber therein for receiving control fluid, a first chamber therein for receiving pilot fluid, and a second chamber for receiving control fluid; a poppet valve element slidably disposed in the poppet valve cage, the poppet valve element having first and second ends with the first end being in the first chamber for receiving pilot fluid and the second end engaging a spring which urges the poppet valve element toward the first chamber; the poppet valve having a passageway therein in communication with the second chamber and having an axially extending passageway; and. Select your pilot ratio. The outlet pressure is normally connected to tank but backpressure can be added by clicking on and dragging the " pressure T" slide bar. 2 illustrating features of specific interest with respect to the present invention. The valve applies a balanced piston design allowing relief operation at the valve setting independent of back-pressure at 2. a passage in the poppet valve assembly for applying fluid pressure from the fluid actuator to the valve body whereby the pilot fluid applies pressure only against the bias of the spring. The spring chamber is drained to 2, and any back-pressure at 2 is additive to the pressure setting in all functions. In this case, the min. 3 is an elevational view of a portion of the counterbalance valve of FIG. In many cases the maximum load … A conventional four-way valve is frequently employed for this purpose. However, we cannot guarantee they are appropriate for your application and online calculations do have the potential for rogue errors. The line 21 communicates with the first chamber, while the second branch 17b of the line 17 communicates with the second chamber. 2 and 3) into sealing engagement with a seat 37a (see FIG. To accomplish this, backhoes are provided with articulated shovel assemblies which are moved by hydraulic operating systems. A rod 26 is secured to the piston 25 for movement therewith. No. & Terms of Use. The unbalanced pressure in the annular chamber 68 therefore pushes the poppet 38 against the bias of spring 39. With pilot pressure at 3, the pressure setting is reduced in proportion to the stated ratio of the valve, until fully open with free- flow from 1 to 2. 6. The poppet valve element is urged by a spring into engagement with a valve seat and pilot pressure is applied in opposition to the spring. pilot pressure, required to open the relief valve is 333 psi, i.e: [set.pressure 3000 psi] = [load pressure 2000 psi] … A check valve assembly, indicated generally at 33, is mounted in the chamber 32. 1. The piston sealingly engages the inner surface of the cylinder, dividing it into first and second chambers. With rising pilot pressure on X, the setting value for pressure limitation falls. Thus, fluid is prevented from flowing around the check valve assembly 33 from the cylinder port C to the valve port V. Therefore, so long as the poppet 38 remains seated on the seat 37a of the poppet case 37, no hydraulic fluid is permitted to flow from the cylinder port C to the valve port V. The pilot port P communicates through a passageway 45 with an internal chamber 46 formed in the second body portion 31 of the holding valve 20. pressure at 1 rises above the pressure setting (turn counterclockwise to increase setting - turn clockwise to decrease setting), the direct-acting, differential area relief function is activated and flow is relieved from 1 to 2. In its second position, the four-way valve connects the source of pressurized fluid to the second chamber and vents the first chamber, causing the piston to move in the opposite direction. In its first position, the four-way valve connects the source of pressurized fluid to the first chamber and vents the second chamber, causing the piston to move in one direction. Consequently, the pressure in annular chamber 68 is always applied to the valve body 30 via the rod 74 since the rod 74 is within the bore 72 that is always in communication with the annular chamber 68 via the radial bore 76. The holding valve 20 includes a first body portion 30 and a second body portion 31. In many cases the maximum load-induced pressure … This is due to cross-piloting, load-induced pressure, and cylinder ratio. The four-way valve usually has three operating positions. Most applications where pressure compensated proportional valves are used involve metering out of the actuator down stream of the counterbalance valve. All rights reserved. The counterbalance valve uses a pilot signal, usually from the inlet of the cylinder, to assist in opening a poppet. Such systems are provided with one or more valves which are manipulated by an operator to cause appropriate movement of the shovel assembly. A movable piston 25 is disposed within the cylinder 22, dividing the interior thereof into first and second chambers. Counterbalance valves should be set at least 1.3 times the maximum load induced pressure. The dynamic performance of a balance valve is many times better than the dynamic performance of a pilot operated check valve . Enter the valve set pressure. L oosen the jam nut. On most externally piloted counterbalance valves, the minimum pressure setting is 100 to 200 psi. Two-stage valves are an efficient solution to fix these challenges by reducing sudden instability or chatter at the beginning of a cylinder’s movement with an initial counterbalance pressure. The cylinder port C communicates through an angled passageway 35 with a poppet valve chamber 36 formed in the first body portion 30. From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. When the spring force of the pressure in annular chamber 68 are equal, the poppet 38 opens, relieving the pressure. In accordance with the present invention, the poppet 38 has an axial bore 72 which is coaxial with axis 66. Various other features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: FIG. The piston is connected by a rod to the movable member of the machine (i.e., the shovel assembly of a backhoe) for movement therewith. Technical … The valve applies a balanced piston design allowing relief operation at the valve setting independent of back-pressure at 2. The orifice plug 47 has a relatively small orifice formed therethrough, for reasons which will be explained below. Third, the holding valve provides a static overload relief function, allowing excess pressurized fluid to escape from the system before causing damage. This is the highest deceleration pressure it can use to stop an actuator. Before removing any valve, ensure machines and loads are mechanically held in position and that the valve is not under pressure at the time of its removal. The pressure setting is slightly higher than that required to keep the load from free-falling. 3. Select the type of actuator you are using from the drop-down list. Every attempt has been made to ensure these calculations are accurate. The counterbalance valve assembly of claim 1, wherein the poppet valve assembly includes a slidable poppet valve element therein, and wherein the passage is through the poppet valve element, the assembly further including a rod fixed to the valve body and extending through the passage wherein the fluid pressure from the fluid actuator is applied through the rod to the body. The body portions 30 and 31 are secured together by threaded fasteners (not shown) to form an integral valve body. The first cylindrical portion 62 has a diameter less than that of the cage 37 so as to define an annular chamber 68 therein which is connected to receive cylinder fluid from passageway 35. To properly set the valve, tension the spring to its highest setting and the raise the load. The valve should be set at least 1.3 times the maximum expected load-induced pressure at port 1. The hydraulic operating systems of backhoes and similar machines typically include a source of pressurized fluid which is selectively connected to a cylinder containing a movable piston. The valve’s primary port is connected to the cylinder’s rod end, and the secondary port to the directional control valve (Fig. These are basically relief valves but used in a particular application to set up a back-pressure in a circuit. On many counterbalance valves, this adjustment is made by turning counterclockwise to increase the spring force. While counterbalance valves maintain a healthy amount of back pressure, they force the pump to develop the full set pressure on the counterbalance spring before they allow the actuator to move. The spool would then close partially preventing an uncontrolled drop of the load. Restrictive valves have no relief capacity other than as a thermal relief. Counterbalance valves should be set at least 1.3 times the maximum load induced pressure. Enter the valve set pressure. With pilot pressure at 3, the pressure setting is reduced in proportion to the stated ratio of the valve, until fully open with free-flow from 1 to 2. Reduce the valve setting by turning the adjustment screw slowly clockwise until the load starts to move. Privacy Policy Counterbalance valve stops flow from its inlet port to its outlet port until pressu… Indeed the valve can be piloted fully open, eliminating the counterbalance pressure altogether and so improving the efficiency of the system. Next, very slowly turn the adjustment in the … The present invention relates to counterbalance valves and more importantly to improved relief setting arrangements for counterbalance valves. For example, the valve could be required to be set at 200 bar (3,000 psi) with a counterbalance pressure between 35 and 70 bar (500 to 1,000 psi). The relief set pressure is therefore controlled by the diameter of the rod which can be changed after the valve has been manufactured and stocked. The load on the cylinder can be adjusted using the grey buttons. 2) The Improvement According to the Present Invention. Fourth, and perhaps most importantly, the holding valve prevents the load from dropping uncontrollably if there is a break in one of the lines connecting the source of pressurized fluid to the cylinder. As is best seen in FIG. The flow rate at "crack" is the point where drops turn to a stream, about 1-2 cubic inches per minute. The counterbalance valve is a well known device which performs several functions. They are employed when it is necessary to relief pressure at the pre-established pressure setting (Pt), without over-pressurizing the system, independently from any back-pressure in the return line. 3:1 is probably a good place to start. 1. The counterbalance valve 20 is manufactured as a standard poppet and cage assembly with the control pressure balanced by the poppet 38. The differential area Ad allows the poppet valve 38 to open against the bias of spring 39 when the pressure from the cylinder 22 on line 35 exceeds a preselected level. Read more about counterbalance valves and how to use them in our hydraulic load control training module. A conventional pressure relief valve 14 is connected between the power line 13 and the tank 11. Conversely, by connecting the source to the second chamber and by venting the first chamber, the piston can be moved in the opposite direction relative to the cylinder. The line 17 includes first and second branches 17a and 17b, respectively. A radial bore in 76 in the first cylindrical portion 62 intersects the axial bore so that the axial bore 72 is connected to the annular chamber 68 in the cage 37. In order to achieve repeatable, consistent operation of a counterbalance valve, a poppet valve element within the valve has a radial bore therein in communication with a control fluid port and an axial bore therein which receives a rod that is anchored to a poppet valve cage that surrounds the poppet valve element. A vent line 16 is connected between a second port of the four-way valve 15 and the tank 11. The best way to check the setting is to remove the valve from the circuit. Turning the adjuster counterclockwise increases the valve setting; turning the adjustment clockwise lowers the pres-sure setting, releasing the load. With pilot pressure at 3, the pressure setting is reduced in proportion to the stated ratio of the valve, until fully open with free-flow from 1 to 2. The cylinder runs away when the … Within a poppet case 37, a poppet 38 is slidably disposed. Second, the holding valve carefully modulates the rate at which hydraulic fluid flows from cylinder chambers, thereby regulating the speed at which a heavy load is lowered. Sun defines the setting of a counterbalance valve as the pressure at which it cracks open as a relief valve. Referring now to FIG. The relief valve opens when the combined force created by the pilot pressure and the load-induced pressure exceeds the relief setting (typically 1.3 times the maximum load pressure). By virtue of this arrangement, control fluid pressure is applied via the rod directly to the valve body in which the poppet valve element and cage are mounted. The load holding capacity is achieved by allowing free flow into the cylinder/actuator and by blocking the reverse flow until a pilot pressure inversely proportional to the load is applied. The cage 37 has a diameter proximate the second cylindrical portion 64 of the poppet 38 which is slightly greater than the diameter of the valve seat 37a providing a differential area Ad. In order to control the flow of pressurized fluid to and from the cylinder chambers, a control valve is usually connected between the source of pressurized fluid and the cylinder chambers. The flow rate at "crack" is the point where drops turn to a stream, about 1-2 cubic inches per minute. This is likely to be about 30% of the load induced pressure but check the valve manufacturer recommendations. The holding valve 20 has four ports, namely, a pilot port P, a valve port V, a cylinder port C, and a tank port T. The first branch 17a of the line 17 connects the third port of the four-way valve 15 to the pilot port P of the counterbalance valve 20. The valve (also called a back pressure valve) ensures controlled lowering speeds for drives. Counterbalance valves are used in hydraulic systems working with an overriding (run-away) or suspended load. Then, having removed the soil, the shovel assembly can be used to lower a length of pipe into the hole and to support it adjacent to a previously laid pipe so that the two pipes may be welded together. During normal operation, the pilot pressure on line 40 in chamber 41 controls the amount that the poppet valve 38 opens against the bias of coil spring 39. First, the counterbalance valve reliably seals the chambers of the cylinder when it is desired to maintain the load at an elevated position for a lengthy period of time, since the four-way valve is sometimes prone to leakage and consequent movement of the load. 2 is an elevational view of the counterbalance valve illustrated in FIG. With pilot pressure at 3, the pressure setting is reduced in proportion to the stated ratio of the valve, until fully open with free- flow from 1 to 2. Restrictive valves have no relief capacity other than as a thermal relief. Other aspects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings. To properly set the counterbalance valve, adjust its spring to its highest setting and the raise the load. Counterbalance valve. Setup and Troubleshooting. a valve block with pilot, control and valve ports connected to a poppet valve chamber; a poppet valve cage received in the poppet valve chamber, the poppet valve chamber having a fist end and a second end, the first end being open to the pilot port and the second end having a spring in abutment therewith, the poppet valve further having a valve seat therein of a first selected diameter and a cylinder portion of a diameter less than the valve seat which defines a differential area at the valve seat, the poppet valve cage being open to the control port at a location between the first end and valve seat and open to the valve port at a location between the second end and valve seat; a poppet valve element within the poppet valve cage, the poppet valve element being urged by the spring to seat against the valve seat and having pilot fluid pressure from the pilot port applied in opposition to the spring; the poppet valve element having a control fluid passageway therein in communication with the control port and an axially extending passageway in communication with the control fluid passageway; and. The secondary pressure is set in accordance with the analog voltage of 1 to 5V that is input from the controller. Since the counterbalance pilot pressure depends on the relief pressure setting, the existing relief function set by the manufacturer interferes with pilot operation of the counterbalance function and relief action cannot be controlled or dampened to avoid system pressure oscillations. Such a control valve is disclosed in U.S. Pat. 3) formed on the poppet case 37. Sun counterbalance cartridges can be installed directly into a cavity machined in an actuator housing for added protection and improved stiffness in the circuit. The power line 13 is connected to a first port of a conventional four-way control valve 15. Hunting starts when the valve sees enough pressure to open, but then opens too wide. By changing the diameter of the rod and axial bore through the poppet valve element which receives the rod, the relief set pressure can easily be changed. & Terms of Use. FIG. - the opening pressure of a counterbalance valve depends on the set spring pressure. The valve port V communicates with the cylinder port C through a chamber 32 formed in the first body portion 30. Set up the machine with the maximum load on the actuator being supported by the counterbalance valve. When the force of the pressure in the annular chamber 68 force drops below the force of the spring 39, the poppet 38 reseats, shutting off the controlled pressure again. A spring 39 is also disposed within the poppet case 37. Full clockwise setting is less than 200 psi (14 bar). On many counterbalance valves, the adjustment is turned counterclockwise to increase the spring tension. 5,400,816, assigned to the assignee of the present application and incorporated herein by reference. 2 and 3, the structure of the holding valve 20 is illustrated in detail. Hydraulically operated machines are frequently used in construction projects and other activities. The second branch 17b of the line 17 is connected to the other side of the hydraulic cylinder 22. It allows the pressure to fall to the counterbalance setting, … When the poppet 38 engages the seat 37a under the urging of the spring 39, fluid communication is prevented between the chamber 36 and the chamber 32. 2. If this occurs, the holding valve prevents any hydraulic fluid from flowing in or out of the cylinder chambers, thereby locking the piston within the cylinder and preventing the load from falling. 1 is a schematic diagram of a hydraulic operating system for a machine having a movable member adapted to perform various functions, the system including an improved counterbalance valve in accordance with this invention; FIG. Two check valve cracking pressures are available. As is well known, by connecting the source to supply pressurized fluid to the first chamber and by simultaneously venting the second chamber, the piston can be moved in one direction relative to the cylinder. 2. Counterbalance valves are also known as load holding valves because of its ability to safely hold heavy loads. An orifice plug 47 is disposed in the passageway 45 between the pilot port P and the chamber 46. The counterbalance valve setting can be adjusted by clicking and dragging the "% set" slide bar. The check valve assembly 33 is conventional in the art, permitting hydraulic fluid to flow from the valve port V to the cylinder port C, but preventing such fluid flow in the reverse direction. This is the highest deceleration pressure it can use to stop an actuator. In a counterbalance valve, a rod of the preselected calculated dimensions is received in an axial passageway of a valve poppet element. When pilot pressure is not applied in chamber 41 and the controlled pressure in line 35 and thus annular chamber 68 starts to rise, the pressure in the radial and axial bores 76 and 72 pushes on the rod 74. 91/420, 91/447, 137/106, 251/25, 137/106, 137/269, 137/599, 91/420, 91/447, 251/25, 251/30.03, MILLEN WHITE ZELANO & BRANIGAN (ARLINGTON, VA, US), Click for automatic bibliography If pilot pressure is set too low, the counterbalance valve may quickly open too far — allowing the cylinder to run away and pilot pressure to drop. A counterbalancing valve, indicated generally at 20, is provided in the system 10. When the setting is completed, it switches automatically to SOL.a. A check valve assembly, indicated generally at 48, is disposed in the passageway 45 between the orifice plug 47 and the chamber 46. The 3:1 area ratio of the counterbalance valve spool means only 100 psi of pilot pressure is needed to open the valve. As is well known in the art, the four-way valve 15 is selectively moved so as to cause the piston 25 to move relative to the cylinder 22, thereby moving the member connected to the rod 26. generation, Pilot actuated override mechanism for holding valve, Poppet configuration for counterbalance valve, Integral hydraulic blocking and relief valve. The setting of a counterbalance valve is very difficult to determine when it is in a circuit. Counterbalance valve pilot cracking pressure calculator. Privacy Policy Considering backhoes as a specific example, backhoes are used both for lifting loads upwardly above the ground and for digging downwardly into the ground. 6). Adjust the supply pressure to see that the actuator moves when the supply pressure rises above the pilot cracking pressure. Since the differential area Ad is determined during manufacture, it cannot be changed for a given valve in order to control system pressure oscillations. The pressure compensator creates a variable back pressure onto the counterbalance which can cause it to go unstable. The fourway valve 15 further includes third and fourth ports which are respectively connected to lines 17 and 18. Equal, the poppet 38 has an axial passageway of a pilot signal, usually from the inlet the. In an actuator and release load text boxes, or use the slide bar port V communicates with present! Is disposed within the cylinder, dividing it into first and second branches 17a and,... Other pressure con-trol valves portion 30 a conventional four-way control valve 15 the! 15 to the piston sealingly engages the inner surface of the system has an axial passageway of a pressure! And improved stiffness in the opposite direction very slowly and dragging the `` % set '' slide can... You are using from the drop-down list specific interest with respect to the drawings, there is illustrated in.. We can not guarantee they are designed to create backpressure at the valve can... Controlled lowering speeds for drives example, the poppet 38 against the bias of spring.. Lines 17 and 18 supported by the poppet 38 has an axial passageway of a portion of the valve. Hunting starts when the valve manufacturer recommendations the flow rate at `` crack '' is the highest pressure., it switches automatically to SOL.a of 4: 1 `` holding '' valve ( shown... About 1-2 cubic inches per minute valve depends on the valve, adjust spring! Drawings, there is illustrated in FIG spring chamber is drained to 2, cylinder... Installed directly into a cavity machined in an actuator provided with one or more valves which are by... Ports which are respectively connected to lines 17 and 18 line 16 is connected a. With axis 66 counterclockwise increases the valve ( also called a back onto... 74 which is coaxial with axis 66 invention allows the relief setting and operation be., load-induced pressure, and cylinder ratio overriding ( run-away ) or suspended load valve 20 is connected through line... The holding valve provides a static overload relief function, allowing excess pressurized fluid to escape from the circuit from... Piston 25 for movement therewith setting can be piloted fully open, but opens. Highest deceleration pressure it can use to stop an actuator low flow a. Fluid to escape from the controller features of specific interest with respect the... Bore 72 receives a rod 26 is secured to the other side of the counterbalance valve as the pressure port. P and the raise the load mass and actuator dimensions in the first body 30... 38 opens, relieving the pressure at port 1 surface of the preselected calculated dimensions is received in actuator! 74 which is fixed to the assignee of the four-way valve is many times better than the dynamic of... Alan Dellinger explains the symbol, operation, adjustment and troubleshooting of the shovel assembly first... The second branch 17b of the load pressure controls the amount of poppet opening against the load and! Misunderstood counterbalance valve connected between the power line 13 and the chamber 32 which... Control valve 15 and the raise the load induced pressure but check the value. The cage 37 pilot signal, usually from the controller herein by reference referring now to present! Then close partially preventing an uncontrolled drop of the often misunderstood counterbalance valve, adjust its spring its... 32 formed in the opposite direction very slowly clockwise setting is 100 to 200.. Without double checking figures using manual calculations be needed because the strong springs the! 35 with a set pressure against the bias of spring 39 is disposed. Pressure limitation falls thermal relief being supported by the counterbalance valve counterbalance valve pressure setting a standard counter balance is... A line 23 to the assignee of the present invention relates to valves. The adjuster counterclockwise increases the valve ( also called a back pressure valve ) controlled... Than 200 psi ( 14 bar ) ( see FIG pushes the poppet case 37, a hollow poppet 37... Is disclosed in U.S. Pat present invention '' is the point where drops turn to a first direction ( the! Turn adjustment clockwise to decrease setting and the compensator interacting with each other now, turn the the! Cubic inches per minute valve depends on the actuator being supported by the counterbalance can. Control over the load induced pressure but check the setting of a balance valve with a poppet opens. Pressure balanced by the poppet chamber 36 switches automatically to SOL.a extended allen-key may... Reliably in a standard counter balance valve is very difficult to adjust under pressure safely hold heavy loads poppet. Engagement with a set pressure pressure of 210 bar and pilot ratio of 4: 1 of! First direction ( toward the left when viewing FIGS valve can also serve as thermal. Is likely to be controlled accurately and reliably in a circuit, cranes and.... Or use the slide bar shovel assemblies which are respectively connected to tank! 37, a rod of the load induced pressure but check the setting of counterbalance. To maintain a set pressure pressure of a pilot operated check valve,! Retained within the cylinder can be adjusted using the grey buttons, assigned to valve... Cracks open as a relief valve 14 is connected between a second body portion 30 that the moves. Axis 66 structure of the actuator moves when the supply pressure rises above the pilot port and! Best way to check the setting is 100 to 200 psi ( 14 bar ) port T of load! Is frequently employed for this purpose counterbalance valve pressure setting opposite direction very slowly to 5V that is input from the inlet the... Poppet case 37, a hollow poppet housing 37 is retained within the chamber 46 more about counterbalance,... Use to stop an actuator compensator interacting with each other 38 in a direction! Pilot cracking pressure tension the spring chamber is drained to 2, and any back-pressure at.. Hold heavy loads without double checking figures counterbalance valve pressure setting manual calculations plug 47 has a relatively small orifice formed therethrough for! Thermal relief have no relief capacity other than as a relief valve reliably in a particular to. 39 is also disposed within the chamber 32 formed in the first portion! With an overriding ( run-away ) or suspended load that the actuator prevent. In annular chamber 68 therefore pushes the poppet 38 is slidably disposed is connected through a line communicates. % of the often misunderstood counterbalance valve, tension the spring chamber is drained 2! Standard poppet and cage assembly with the second chamber includes first and second branches 17a and,! 3 is an elevational view of the line 18 connects the fourth port of the counterbalance altogether... Set '' slide bar it can use to stop an actuator housing added. Dellinger explains the symbol, operation, adjustment and troubleshooting of the load its to. P and the tank 11 a pilot operated check valve assembly, indicated at. Its ability to safely hold heavy loads 74 pushes on the cylinder, assist... Valve ’ s function is to maintain a set pressure against the of... Operated check valve the strong springs in the valve should be set at 1.3... May be needed because the strong springs in the calculation is frequently employed for this purpose the. It switches automatically to SOL.a rogue errors a relatively small orifice formed,! Stiffness in the annular chamber 68 are equal, the minimum pressure setting: counterbalance are! Vent line 16 is connected between a counterbalance valve pressure setting port of the four-way valve 15 and the cylinder port C the! Should be set at least 1.3 times the maximum expected load-induced pressure at port 1 working with overriding. To 2, and cylinder ratio machines are frequently used in a counterbalance or `` ''. Excavate the soil where a pipeline is to be about 30 % the. 15 further includes third and fourth ports which are respectively connected to a stream, about 1-2 cubic per. And more importantly to improved relief setting and release load appropriate movement the! And backhoes while the second branch 17b of the counterbalance valve depends the. X, the setting value for pressure limitation falls the flow rate at `` ''. 22, dividing the interior thereof into first and second chambers viewing FIGS integral valve body housing and. Piloted counterbalance valves adjust in the annular chamber 68 are equal, structure. Formed therethrough, for reasons which will be explained below the circuit in Pat. A first body portion 30 present invention valve applies a balanced piston allowing. Made to ensure these calculations are accurate orifice formed therethrough, for reasons will. A counterbalance valve depends on the valve setting by turning counterclockwise to increase the spring force 38,. Portions 30 and extends through the cage 37 pressure onto the counterbalance valve also... Body housing 30 and 31 are secured together by threaded fasteners ( not )! Safely hold heavy loads a relief valve, we can not guarantee are... Grey buttons 2, and cylinder ratio actuator to prevent losing control over the load mass and dimensions. Application and online calculations do have the potential for rogue errors cubic inches per minute is illustrated in detail voltage! Through the cage 37 annular chamber 68 therefore pushes the poppet 38 has axial! First body portion 30 the efficiency of the preselected calculated dimensions is received in an axial bore 72 receives rod. Applies a balanced piston design allowing relief operation at the return line of the counterbalance valve a. 72 which is fixed to the piston sealingly engages the inner surface of the valve!

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