Wilkins Reduced Pressure Principle 375XLB 1-1/4”

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, remove screw and seal ring retainer

Inspect seat surface for nicks or dings and replace if necessary

Attach the "HIGH" hose to test cock #2 and the "LOW" hose to test cock #3

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

Close by-pass valve "A". Open by-pass valve "B" and bleed to atmosphere until all air is expelled. Close by-pass valves "B" and "C"

Test No. 1 - #2 Check Valve Tightness

Attach the "VENT" hose to test cock #4

Remove three bolts holding relief valve module to body

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

Remove the four screws holding the two module halves together

Remove stem assembly and inspect diaphragm and plunger o-ring for damage

Replace any damaged parts and apply grease to plunger o-ring