Fluid Power General Design Rules and Application
Horsepower for driving a pump:
For every 1 HP of drive, the equivalent of 1GPM @ 1500 PSI can be produced.
Horsepower for idling a pump:
To idle a pump when it is unloaded will require about 5% of its full rated horsepower.
Compressibility of water:
Volume reduction is about 1/3% for every 1000 PSI pressure.
Compressibility of hydrualic oil:
Volume reduction is approximately 1/2% for every 1000 PSI of fluid pressure.
Flow velocity in hydraulic lines:
- Pump suction lines 2 to 4 feet per second
- Pressure lines up to 500 PSI, 10 to 15 feet/sec
- Pressure lines 500 to 3000 PSI, 15 to 20 ft/sec
- Pressure line over 3000 PSI, 25 ft.sec
- All oil lines in air-over-oil system, 4 ft.sec