10. Compressor Valve Assemblies
a. Location. The four compressor valve assemblies are located in the compressor bank cylinder head assembly.
The valve assembly is connected to an automatic-operating pressure control system.
b. Purpose. The valves operate to admit and discharge air from the compressor cylinder. Free air is admitted
through the air cleaners and the intake valve part of the assembly by the action of the piston on its downward stroke. As
the piston moves up from bottom dead center, the suction valve is closed. When the pressure in the cylinder rises slightly
above that in the discharge manifold, the discharge valve port of the assembly will open, allowing air in the cylinder to flow
into the compressor discharge manifold. When the air pressure drops to 90 psi in the air receiver, the unloader pilot valve
shuts off air to the suction valve unloaders to close the suction valves. When the air pressure reaches 100 psi in the air
receiver, the unloader pilot valve admits air to the suction valve unloaders to open the suction valves.
Figure 8. Engine and compressor with housing removed.
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