172-65174MA-11 (COSR Pressure Reducing Valve) 16 Feb 2022
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 pilot valve seat, 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.
15 to 50 mm (
1
/
2
to 2 in)
65
– 150 mm (2
1
/
2
–
6 in)
Diaphragm
Pilot Valve Seat
& Gasket
Pilot Valve
Pilot Valve Spring
Plug
Pilot Body
Gasket
Notch
Hex Bolt
Pilot Screen
Pilot Screen Holder
& Gasket
Diaphragm
Pilot Valve Seat
& Gasket
Pilot Valve
Pilot Valve Spring
Plug
Hex Bolt
Pilot Body
Gasket
Notch
Connecting
Tubes
Hex Bolt
Pilot Cover
Pilot Screen
Pilot Screen Holder
& Gasket