Replacement Diaphragm for Galcon Valves (3/4" and 1")

A quick guide to rebuilding your valve and restoring a leak-free seal.

Step 1: Turn Off the Water
Before attempting any valve maintenance, ensure the main water supply to your irrigation manifold is completely turned off and the line is depressurized to prevent blowouts.

Step 2: Remove the Valve Bonnet
Using a screwdriver or wrench, carefully remove the screws or bolts holding the top of the valve (the bonnet) in place. Lift the bonnet slowly, being very careful not to lose the internal spring.

Step 3: Swap the Diaphragm
Remove the torn or degraded old diaphragm. Wipe the inside seating area of the valve body with a clean, damp cloth to remove any sand, grit, or mineral scale. Place the new diaphragm inside, ensuring any alignment holes perfectly match the valve body.

Step 4: Reassemble and Test
Place the internal spring back into position and secure the bonnet over the top. Tighten the screws evenly in a cross pattern. Turn the main water supply back on and check the valve to ensure it opens and closes without weeping.

As I start my system this spring, how do I know if I need a new Replacement Diaphragm for my Galcon 3/4" or 1" Valves?
If your valve continuously weeps water or fails to close completely during spring startup, the old rubber likely tore during a winter freeze. Swap it out to restore a leak-free seal.

Spring startup is the most common time to discover valve damage. Replacing the internal diaphragm is much faster and cheaper than cutting out the entire valve and replumbing the manifold.

Will this Replacement Diaphragm fit valves from other brands?
No, this Replacement Diaphragm is designed exclusively for Galcon brand 3/4-inch and 1-inch automated valves. It will not fit Hunter, Rain Bird, or DIG valves.

Every manufacturer uses a proprietary shape, seating ring, and screw pattern for their diaphragms. Always verify the brand stamped on your valve before purchasing replacement parts.

Does the Replacement Diaphragm for Galcon Valves come with a new internal spring?
No, the Replacement Diaphragm for Galcon Valves includes only the rubber diaphragm itself. You must carefully retain and reuse the original spring from your existing valve.

Be very careful when removing the bonnet of your valve to access the old diaphragm, as the internal spring can easily pop out and get lost in the dirt.

How should I prep the valve body before installing the Replacement Diaphragm for Galcon Valves?
Before installing the Replacement Diaphragm for Galcon Valves, wipe the inside seating area with a clean, damp cloth to remove any sand, grit, or mineral buildup that could prevent sealing.

Even a single grain of sand trapped under the new rubber diaphragm can prevent it from sealing completely flush, causing the valve to continue weeping even with a brand new part.