TM 5-3805-281-24-1
Theory of Operation
ARM HEAD END REDUCED LEAKAGE VALVE OPERATION
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tank through the pilot valve (E). The return pressure
The function of the arm head end reduced leakage
from the cylinder head end pushes the poppet off its
valve (G and H) to reduce cylinder drift by reducing
seat opening the passage for oil to flow to return. The
leakage from the cylinder head end back through the
poppet is pushed off its seat because the OD of the
control valve. The illustration shows the operation for
upper land at the head end of poppet is slightly larger
arm-in function.
than the lower land.
Actuating the pilot controller for arm-out function also
The relief valve (B) is used to protect the circuit in
sends the arm out pilot pressure signal (F) to shift the
neutral.
pilot valve (E). The pressure applied to the check valve
poppet (C) spring chamber is released to hydraulic oil
Continued on next page
CED,TX08227,3167
1903JUN981/2