Wenzhou Prance Hydraulic Equipment Co., Ltd
Aeration means free air is entering or remaining in the oil; cavitation means local pressure falls low enough for vapor cavities to form and collapse. They can sound similar and may occur together, so diagnosis should combine inlet pressure
Inlet vacuum is the pressure below local atmospheric pressure at the pump inlet. Judge it against the exact pump documentation and the actual oil temperature, speed, altitude, and test-point location. One universal vacuum limit cannot safel
Size the suction line from the required inlet flow, the pump maker’s permitted inlet pressure, fluid viscosity, hose construction, fittings, and the worst cold-start condition. A larger nominal hose is not automatically adequate when a long
Hydraulic valve spool overlap describes the relationship between spool lands and metering edges around the neutral position. Positive overlap creates a deadband before a port opens, zero overlap aims for an immediate transition, and negativ
A hydraulic valve flow rating is meaningful only with its stated pressure drop, fluid, viscosity, temperature, spool path, and duty. A catalog's nominal flow is not a promise that every metering path will pass that flow with acceptable loss
Open center vs closed center hydraulics describes what the supply path does when directional valves are neutral. An open-center valve provides a low-pressure path toward tank for a compatible fixed-displacement supply. A closed-center valve
A hydraulic motor counterbalance valve meters outlet flow so an overrunning load cannot drive the motor uncontrolled. Pilot pressure opens the valve during commanded motion, while the setting maintains enough resistance to stabilize the loa
A hydraulic motor crossover relief valve connects one motor work port to the other when differential pressure exceeds its setting. It can limit shock during reversal or deceleration, but it does not automatically provide controlled overrunn
Hydraulic motor efficiency calculation separates volumetric efficiency, mechanical efficiency, and overall efficiency. Volumetric efficiency compares actual speed with the speed predicted from inlet flow and displacement; mechanical efficie
Hydraulic pump destroke testing checks whether a variable-displacement pump reduces output when its control condition is reached. The test must observe pressure, flow, case drain, temperature, command state, and circuit demand together; pre
The load sensing vs pressure compensated pump choice changes how a variable pump decides its displacement. A pressure-compensated pump responds to outlet pressure alone, while a load-sensing control compares pump pressure with a remote load
Hydraulic pump pressure pulsation is the repeating pressure variation created as pumping chambers connect to the outlet and the circuit responds. Its amplitude depends on pump geometry, operating point, trapped-volume timing, fluid compress