Sakai TW504 - Page 77

4-002
HYDRAULIC SYSTEMS
Valves
DESCRIPTION SYMBOL
Check valve
Manual shut off (On-Off)
Pressure relief
Flow control, adjustable
Valve symbols:
The basic valve symbol
one or more squares
with lines representing
ow paths and ow con-
ditions between ports.
Multiple squares indicate
a valve with as many dis-
tinct positions there are
squares providing various
ow path options for the
uid.
The multiple square
moves to represent how
ow paths change when
the valving element is
shifted within the compo-
nent.
Valves with innite posi-
tioning between certain
limits are symbolized
with lines parallel to the
squares.
Methods of Operation
DESCRIPTION SYMBOL
Spring
Manual
Pressure compensated
Reversing motor
Pilot pressure:
Internal supply
Remote supply
Solenoid:
Single winding
Two windings operating
in opposite directions.
Pilot directional valve is
actuated by the solenoid.