Apollo Reduced Pressure Detector Assembly RPDA4A 8”

Test No. 1: Pressure Differential Relief Valve Operation

Open test cock (TC) #4 to establish flow through the RP.

Flush TCs in order without dumping the relief valve

Close test cock #4 and install appropriate adapters in TCs.

Connect the high (left) hose to TC #2 and the low (middle) hose to TC #3.

Fully open the bypass (right) valve.

Slowly open TC #2 and bleed the high side through the bypass hose by opening the high valve. Close the high valve.

Slowly open TC #3 and bleed the low side through the bypass hose by opening the low valve. Close the bypass and low valves after the gauge pointer reaches the upper end of the scale.

Close the No. 2 shutoff valve and observe the pressure drop across check valve No. 1.

Preliminary Steps for 10” & 12” Models

Remove the flow divider (FD) by removing the 1⁄4” nut holding it in place.

Rotate the FD 90° and lift up and out of the valve body.

Ensure the FD’s tab is oriented on the same side as the cover of the relief valve body.

Remove the cover coupling by removing the two bolts and nuts.

Lift off the cover. Ensure the gasket remains on the valve body.

Remove the reusable locknuts on the check seat

Slide the entire check module off the body studs and remove from body.