ENGINEMAN 1 & C
of the pressure control. When a shuttle valve fails
to operate, the stop valves should be closed and
the defective valve removed and repaired.
Incorrectly adjusted needle valves can be
because the valve adjustment may allow more
fluid to pass through leakage points in the system
than through the valve.
another source of trouble. Needle valves which
are adjusted too fine may cause the device
operated by the valve to stop short of its
intended stopping point. This may happen
SERVOVALVES
Although there are many types of valves
used for control in a hydraulic system, the valve
Figure 7-4.Servovalveneutral.
7-20