TM 5-3805-280-24-1
Theory of Operation
boom cylinder to sump. In the down position, pilot oil
Boom cylinder controlled load lowering valves are used
moves pilot valve (1) against spring force closing off oil
in the boom circuit. The function of the boom cylinder
flow from the boom cylinder to spring end of poppet
controlled load lowering valve is to prevent the boom
valve (2). Oil flowing from the boom cylinder to the
from falling by maintaining pressure in the circuit in
plunger side of poppet valve (2) overcomes the spring
case of a rupture.
force and allows oil to flow through valve (3) and back
to sump. Valve (3) is metered open from pilot pressure
Pressure oil from head end of the boom cylinder flows
applied by pilot valve (1).
through pilot valve (1). The oil flows to the spring end
of poppet valve (2), closing the passage of oil from the
CED,OUOE020,75 1926MAY992/2
9025
05
87
6-83