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Eaton Vickers SystemStak Service Line Counterbalance Valve

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Product Details

DGMR-3-50 counterbalance valve. 4401-03; NFPA-D03 Service Line, SystemStak Valves

Description

Vickers SystemStak counterbalance valves are available with single and double control. A relief valve controls flow in one direction, and a check valve allows for free reverse flow. A pilot pressure connection controls the relief valve setting in its counterbalance function.

Counterbalance valves control negative or overrunning loads by preventing an actuator from running ahead of the required flow rate. This capability to provide precise, stable, motion control

makes counterbalance valves ideally suited for use in moving and positioning systems.

Qualification to NFPA 350 bar (5000 psi) ensures the user of both rugged construction and extended life as the valve has been qualified to a worldwide high pressure, multi-million operating cycle specification established by both users and suppliers

Features and Benefits

lCompact hydraulic system through stack mounting.

lImproved system response.

lEliminates system resonance.

lExcellent reliability through high strength components.

lCartridge design permits service without removing valve from stack.

lNo intervalve piping eliminates leaks and reduces installed cost.

lChoice of two pilot ratios for smooth control of loads.

Applications

When used with paired cylinders,counterbalance valves will assist balancing of the load by transferring part of the load from the heavily loaded cylinder to the less loaded cylinder.

When used with open center directional control valves, deceleration control can also be provided.

Two pilot ratios are offered; 4:1 and 10:1.Normally the lower pilot ratio will provide better motion control and stability in systems with high capacitance and high inertia loads. The high pilot ratio is best applied to the control of motors.

A high pilot ratio improves the efficiency of a hydraulic system, but motion control and stability may suffer.

Operating Tips

The minimum pressure setting of a counterbalance valve should be 1,3 times the maximum pressure induced by the load. It is recommended that the pressure adjustment setting of the valve be made on a test stand as it is difficult to achieve an accurate setting when the valve is installed in a system. Normally,a counterbalance valve should not be used in closed loop hydrostatic systems,as it may cause overheating.

Counterbalance valves usually work well with the opening characteristics of most directional valve spools (which open P to A and B to T almost simultaneously). In general they work best with meter-in directional valve spools (which open B toT before opening P to A).