172-65604MA-00 (
PN-COSR
Pneumatic Control Valve) 10 Sep 2014
19
Disassembling the Pilot Section
The diaphragm is removed by utilizing the notch in the pilot body. Loosen the pilot valve
seat with a box wrench and remove it. Lift the pilot valve spring up and out with a pair of
tweezers. Then loosen and remove the pilot screen holder to remove the pilot screen.
Check for any fault on the seating surface of the pilot valve, flaws on the gaskets,
and clogging of the pilot screen.
Check for deformation, corrosion or faults on the diaphragm. The diaphragm should
be convex (open downward), with the printed UP mark on the top.
Diaphragm
Pilot Valve Seat
& Gasket
Pilot Valve
Pilot Valve Spring
Plug
Pilot Body
Upper
Pilot Body
Gasket
Notch
Pilot Screen
Pilot Screen Holder
& Gasket
Hex Bolt
Disassembling the Piston Section
Take the pilot body off after removing the hex bolts. During this process, pay attention
not to lose the connecting tubes (2 pcs).
Remove the piston guide, piston and cylinder from the main body. Then remove the
piston rings and the tension rings from the piston. Do not apply too much force when
removing the piston rings and tension rings.
Check the interior of the cylinder, the exterior of the piston rings, the small hole on
the piston and the cylinder gasket for any fault or abnormality.
Piston Guide
Piston
Piston Ring
Tension Ring
Cylinder
Lower Pilot
Body Gasket
Main Body
Cylinder Gasket
