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Getting started:
Griffco Valves are known for their reliability and durability. However, periodic maintenance, such as replacing the diaphragm, is required to keep the valve in operation. In this guide, we will show you how to replace the internals of a Griffco Back Pressure (BPV) and Pressure Relief Valve (PRV).
Tip: This guide is for the G-Series back pressure valve, but the process is the same regarding disassembly and reassembly for other Griffco Valve series
Follow along with the video tutorial or click the timestamp next to any step to jump to that point in the video.
Info: Recommended Tools
Allen Wrenches sized as follows:
All Plastic G Series Valves use 3/16" Allen Wrench
Metal G Series Valves ½" to 1" use 3/16" Allen Wrench*
Metal G Series High Flow 1" Valves use ¼" Allen Wrench
Metal G Series Valves 1-1/2" to 4" use ¼" Allen Wrench
All M Series Valves use 5/32" Allen Wrenc
Torque Wrench
PA001 Griffco Pressure Setting Adjustment Wrench
Gloves and Clean Cloth
Step-by-Step Guide
Tip: Tap the ▶ Step # to expand or collapse more detailed instructions
Step 1: Ensure Chemical Feed System is Not Under Pressure
Step 1: Ensure Chemical Feed System is Not Under Pressure
Before starting disassembly, make sure that the chemical feed system is not under pressure and that the chemical lines have been flushed with water.
Step 2: Remove Black Protective Cap and Adjust ment Screw
Step 2: Remove Black Protective Cap and Adjust ment Screw
Take off the black protective cap to expose the PET adjustment screw. Use the adjustment tool to mark the line and note the depth of the adjustment screw before removing it.
Step 3: Remove Acorn Nuts
Step 3: Remove Acorn Nuts
Remove the forward acorn nuts using an appropriate T-handle Allen wrench.
Step 4: Remove Spring Support Disc and Diaphragm
Step 4: Remove Spring Support Disc and Diaphragm
Remove the black top, spring support disc, and diaphragm. Inspect the valve seat for damage such as nicks and corrosion. Clean the sealing surface with a white cloth.
Step 5: Reassemble Valve
Step 5: Reassemble Valve
Insert the diaphragm with the PTFE side down first. Make sure it is centered, and then replace the support disc and spring. Make sure the spring is centered and replace the black top.
Step 6: Tighten Bolts and Adjust Pressure
Step 6: Tighten Bolts and Adjust Pressure
Tighten the four bolts. We recommend using a torque wrench to three foot-pounds but begin by making them finger-tight first. Turn the adjustment screw clockwise to approximately the same position as it was prior to disassembly, referencing the pencil mark made earlier. Use a pressure gauge to verify the pressure setting. Turning the adjustment screw clockwise will increase the pressure. Do this with the pump operating under pressure after it is installed to achieve the accurate pressure set.
Your Griffco Valve is now ready for operation.
Still have Questions?
Give us a call at 484-544-0506