Page 8 - Parker - The Handbook of Hydraulic Filtration

Contamination Types and Sources

Filtration Fact External Contamination Sources

System Contamination
Warning Signals
• Solenoid burn-out.

• Valve spool decentering,
leakage, “chattering”.

• Pump failure, loss of
flow, frequent

replacement.
• Cylinder leakage, scoring.

• Increased servo hysteresis.

Filtration Fact

Most system ingression
enters a system through the

old-style reservoir breather

caps and the cylinder rod
Ingression Rates For Typical Systems
glands.

Mobile Equipment 10 -10 per minute*
8
10
8
Manufacturing Plants 10 -10 per minute*
6
Assembly Facilities 10 -10 per minute*
6
5
* Number of particles greater than 10 microns ingressed
into a system from all sources.

Prevention
▼ Use spin-on or dessicant style filters for reservoir air breathers.

▼ Flush all systems before initial start-up.
▼ Specify rod wipers and replace worn actuator seals.
▼ Cap off hoses and manifolds during handling and maintenance.
▼ Filter all new fluid before it enters the reservoir.

6