TM 5-3805-281-24-1
Theory of Operation
PILOT PRESSURE REGULATING VALVE AND FILTER OPERATION
9025
05
3
A--Plug
E--Pilot Pressure
I--Spring
B--Regulated Pilot Oil To
Regulating Valve
J--Pilot Pressure
Pilot Shut-Off Valve
F--Pilot Oil From Pilot
Regulating Valve Spool
C--Return Oil to Hydraulic
Pump
K--Orifice
Oil Tank
G--Pilot Filter and Bypass
L--Pilot Oil From Pilot
D--Regulated Pilot Oil to
Valve
Filter
Control Valve
H--Shim
The pilot pressure regulating valve (E) is a bypass flow
The pilot filter and pilot pressure regulating valve are
regulating valve and is used to regulate the pilot oil
incorporated into one assembly.
pressure in the pilot oil circuit. Pilot oil flows through
the orifice (K) to the end of the pilot pressure
The pilot filter (G) consists of a filter element and a
regulating valve spool (J). When the pressure in the
bypass valve. The bypass valve senses the differential
pilot circuit increases to the pressure setting of the
pressure between the inlet side and outlet side of the
spring (I), the spool is push right against the spring.
filter element. During normal operation, the bypass
Regulated pilot oil flows to the pilot shut-off valve (B)
valve is held closed by a spring and pilot oil flows
and the control valve (D). Oil not needed to maintain
through the filter element and out to the pilot pressure
the pressure in the pilot circuit flows to the hydraulic oil
regulating valve. If the filter element becomes plugged,
tank as return oil (C).
pressure on the inlet side increases forcing the bypass
valve open. Pilot oil now bypasses the filter element
and unfiltered oil flows to the pilot pressure regulating
valve.
TX,05,GG2149
1917NOV971/1
