Wilkins Valve 375XLB

Remove three bolts holding relief valve module to body.

Pull down and remove relief module to expose seat and seal ring.

Inspect the following components without further disassembly

Ensure small o-ring and large o-ring are not lost.

Diaphragm and Stem Assembly Inspection

Remove the four screws holding the two module halves together.

Ensure small o-ring is not lost.

Close inlet and outlet shut-off valves

Open No. 2, No. 3 and No. 4 test cocks to release pressure from valve

Unscrew 4 screws holding body down and lift valve body upward

Twist and remove sleeve from body

Push in outlet end of body to slide out both checks from the body inlet

Twist spring retainers counter-clockwise to remove from seat and access poppets

Inspect the rubber seal ring for cuts or embedded debris

Remove seal ring, invert if possible, and note if replacement is needed

Close test cock #4, and disconnect "VENT" hose from test cock #4

Open by-pass valves "B" and "C" bleeding to atmosphere

Close by-pass valve "B" restoring the system to normal static condition

Observe the pressure differential gauge and note this as the #1 check valve PSID

Is the static pressure drop across #1 check valve greater than the relief valve opening point and at least 5.0 psid?

Attach the 'HIGH' hose to test cock #2

Attach the 'LOW' hose to test cock #3

Open by-pass valves 'C' and 'A' and bleed to atmosphere until all air is expelled

Open by-pass valve 'B' and bleed to atmosphere until all air is expelled

Clean all parts thoroughly with water after disassembly

Inspect rubber seal rings for damage

Test unit after reassembly for proper operation

Refer to 'Testing Procedures' for detailed instructions