TM 5-3895-382-24
With Steering and Load
With Steer and Load.
(10) Pressure passage. (18) Flow passage.
When the steering is operated during a load on the charge
circuit the priority function of the valve is operated. Inlet
pressure in pressure passage (10) increases. High inlet
pressure forces more oil flow to the charge circuit and
decreases flow to the steering circuit. The force on both ends
of priority spool (1) becomes unbalanced. Priority spool (1)
moves to the right as shown. Flow passage (18) decreases,
flow to charge circuit decreases and priority flow to steering is
restored.
Steering Relief
(1) Priority spool. (11) Control orifice. (17) Flow Passage. (20) Steer
relief passage.
A similar condition exists if a load at the charge inlet creates
high pressure. When the inlet pressure is high on the charge
relief side of the valve, priority spool (1) moves to allow more
flow to the charge circuit. The pressure drop increases across
control orifice (11) and moves priority spool (1) to the left as
shown.
The priority flow is metered at flow passage (17). Control
orifice (11) is designed to maintain a constant flow to the
steering circuit. During operation, priority spool (1) will
oscillate.
The location of priority spool (1), as shown, is also the position
during system relief. Steering relief pressure is limited to
13 000 kpa (1885 psi). Relief oil exits the valve through relief
passage (21).
14-11
