Optimum Cleanliness Level Codes for Hydraulic Componentry
Hydraulics systems by nature, can be very susceptible to contamination. As a result various components have different tolerances to contamination within an array of hydraulic systems. Extensive research carried out by dedicated hydraulic specialists have produced target cleanliness grades for operators to use as a guide to increase the reliability of systems across industry.
For example, a system that has gear pumps, poppet valves and hydraulic cylinders will not require the stringent demands that a system using piston pumps, servo valves and piston motors does.
Below is a chart with target cleanliness grades enabling operators to achieve high levels of reliability in their operations.
Pressure | <2000 psi <140 bar | <3000 psi 2100 bar | >2000 psi > 140 bar |
|---|---|---|---|
Pumps |
|||
| Fixed Gear | 20/18/15 | 19/17/15 | 18/16/13 |
| Fixed Vane | 20/18/15 | 19/17/14 | 18/16/13 |
| Fixed Piston | 19/17/15 | 18/16/14 | 17/15/13 |
| Variable Vane | 19/17/15 | 18/16/14 | 17/15/13 |
| Variable Piston | 18/16/14 | 17/15/13 | 16/14/12 |
Valves |
|||
| Direction (solenoid) | 20/18/15 | 19/17/14 | |
| Pressure (modulating) | 19/17/14 | 19/17/14 | |
| Flow Controls (standard) | 19/17/14 | 19/17/14 | |
| Check Valves | 20/18/15 | 20/18/15 | |
| Cartridge Valves | 20/18/15 | 19/17/14 | |
| Screw-In Valves | 18/16/13 | 17/15/12 | |
| Prefill Valves | 20/18/15 | 19/17/15 | |
| Load-Sensing Directional | 18/16/14 | 17/15/13 | |
| Hydraulic Remote Controls | 18/16/13 | 17/15/12 | |
| Proportional Directional (throttle) | 18/16/13 | 17/15/12 | |
| Proportional Pressure Controls | 18/16/13 | 17/15/12 | |
| Proportional Cartridge Valves | 18/16/13 | 17/15/12 | |
| Proportional Screw-In Valves | 18/16/13 | 17/15/12 | |
| Servo Valves | 16/14/11 | 15/13/10 | |
Actuators |
|||
| Cylinders | 20/18/15 | 20/18/15 | 20/18/15 |
| Vane | 20/18/15 | 19/17/14 | 18/16/13 |
| Axial Piston Motors | 19/17/14 | 18/16/13 | 17/15/12 |
| Gear | 21/19/17 | 20/18/15 | 19/17/14 |
| Radial Piston Motors | 20/18/14 | 19/17/15 | 18/16/13 |
| Swashplate Design Motors | 18/16/14 | 17/15/13 | 16/14/12 |
Hydrostatic Transmissions |
|||
| Hydrostatic Transmissions (in-loop fluid) | 17/15/13 | 16/14/12 | 16/14/11 |
This information was taken from the Certified Fluid Power Electronic Specialist Study Manual dated 18/12/09 and is found on page 10-30.