Hunter Industries Hunter PGV Diaphragm Irrigation Valve Replacement, Fits 3/4" & 1" PGV, SRV, ASV Valves, Leak Free Double-Beaded Seal, Easy Install, OEM Sprinkler Repair Part, Model 332100

Why I reached for the Hunter PGV diaphragm

Irrigation valves rarely fail all at once; they start seeping, a zone won’t shut off fully, or the lowest head dribbles long after a cycle. In most cases, the diaphragm inside the valve is the culprit. Rather than cutting pipe and replacing a complete valve, I tested the Hunter PGV diaphragm as a drop-in repair on a few tired 3/4- and 1-inch Hunter valves (PGV and PRO-ASV) on a residential system. The promise is straightforward: loosen four bolts, swap the diaphragm, restore full shutoff. That’s exactly what I experienced.

Design and compatibility

This diaphragm is an OEM part from Hunter, and it shows in the fit. The molding lines are clean, the central plunger is captive (so you’re not chasing a loose piece in a muddy box), and the double-beaded sealing surface is noticeably sturdier than the generic flat-lipped diaphragms I’ve seen. It’s made for Hunter’s plastic 3/4- and 1-inch bodies, including PGV (jar-top and bolted bonnet), SRV, ASV, PRO-ASV, and the PGV-100/101 variants. If you’re working on metal valves, larger sizes, or non-Hunter bodies, this isn’t the right part.

One practical note: jar-top PGV valves don’t use screws for the lid, but the diaphragm underneath is the same style. On the older bolted PGVs and the anti-siphon variants, those four stainless bonnet screws are captive and thread into brass inserts—reassuring for repeated service.

Installation experience

Each swap took me 10–20 minutes, start to finish, including cleaning the valve seat and flushing debris. Here’s the flow that worked best:

• Shut off the irrigation supply at the isolation valve and open the zone manually to relieve pressure.
• In the valve box, brush away soil from the bonnet so it doesn’t fall inside when you open it.
• Loosen the four screws a little at a time in a cross pattern. On older installs, mine were tight from mineral buildup; a stubby Phillips and a 1/4-inch nut driver both helped. No special tools are required, just basic hand tools.
• Lift the lid, note the spring orientation, and remove the old diaphragm. If the plunger on your old unit isn’t captive, watch for small parts.
• Clean the valve seat and the small bleed ports in the body. I use a soft nylon brush or a cotton swab—no abrasives. A quick flush helps: briefly crack the water on with the lid off and your hand shielding the opening to push grit out and away.
• Drop in the new diaphragm and spring, align the holes, and reinstall the bonnet. Tighten the screws evenly in a cross pattern; snug, not gorilla-tight.
• Reset the flow control (if your valve has one) near its previous position, then test manually and via the controller.

What stood out was how forgiving the captive plunger design is. On one valve, I opened the bonnet in a muddy box after a rain; having the plunger integrated meant I didn’t lose anything in the mess. The double-beaded edge seated against the body without fuss—no need for sealant or grease.

Performance

Before the swap, one PGV zone showed a steady seep at the lowest head; another wouldn’t fully close after manual bleed. After the diaphragm replacement, both zones snapped shut cleanly, and the telltale dribble stopped. The valves also responded more consistently to manual operation; the bleed screw opens gave a crisp start and stop rather than a soggy, lagging close.

On anti-siphon (PRO-ASV) valves installed higher than the downstream heads, the new diaphragm restored a positive seal that resisted small bits of debris much better than the fatigued, cupped rubber I pulled out. The double-beaded seal appears to conform well to minor imperfections in the valve seat. I saw no water hammer or chattering after the swap, which can happen if the spring is installed upside down or the flow control is cranked too far shut—worth checking if you notice noise.

Durability so far

After a season of use (hot days, occasional dirty water after line breaks), the diaphragms I installed are still supple and leak-free. The bead has not taken a visible set, and I haven’t needed to retighten bonnet screws. I wouldn’t expect rubber components to last forever, but the construction here feels on par with Hunter’s original assemblies. I tossed a spare in my irrigation kit; these are compact and an easy on-the-spot save when a valve starts weeping mid-season.

What it won’t fix

A fresh diaphragm won’t mask deeper problems. If the valve body is cracked, the seat is gouged, or the solenoid is sticking or has a swollen O-ring, you’ll still have issues. I had one zone that continued to pass water after the swap; the cause wasn’t the diaphragm at all—it was debris jammed in a downstream check nozzle. Flush both sides of the valve before declaring the repair a failure.

Two other caveats:
- Inspect the diaphragm before installing. A small nick or molding defect at the bead will cause a persistent seep that looks like a seat problem.
- Confirm your valve family and size. This unit is for Hunter 3/4- and 1-inch plastic valves; it won’t fit 1-1/2-inch bodies or non-Hunter valves.

Value

The math favors this fix. Replacing a whole valve means cutting PVC, gluing couplings or unions, and often digging in cramped boxes. With this diaphragm, I spared the pipe work, kept the existing wiring and manifold intact, and restored function in minutes. In water savings alone—eliminating that slow drain at the lowest head—the cost pays back quickly. If you maintain several zones or multiple properties, keeping two or three of these on hand makes sense.

Tips and best practices

• Photograph the valve before disassembly so spring and diaphragm orientation are easy to replicate.
• Clean the bonnet threads and use a light touch when tightening; you’re compressing a gasket, not torquing a lug nut.
• If a zone still leaks, back out the manual bleed screw and re-seat it; also verify the flow control isn’t opened all the way.
• Flush upstream after main-line repairs; grit is the enemy of diaphragms.
• For jar-top PGVs, hand-snug is sufficient; don’t use pliers on the lid.

Pros

• OEM fit across popular Hunter 3/4- and 1-inch valves (PGV, SRV, ASV, PRO-ASV)
• Double-beaded seal provides a reliable, leak-resistant closure
• Captive plunger simplifies installation and reduces lost-part mishaps
• No cutting, gluing, or wire work—fast repair with basic tools
• Restores performance and saves water with minimal downtime

Cons

• Won’t resolve issues from cracked bodies, damaged seats, or faulty solenoids
• Limited to specific Hunter valve families and sizes
• Tight or corroded bonnet screws can slow the job on older installs
• As with any rubber part, a rare molding flaw can cause a leak—inspect before use

Recommendation

I recommend the Hunter PGV diaphragm for anyone maintaining Hunter 3/4- or 1-inch plastic valves who’s dealing with seepage or incomplete shutoff. It’s a practical, OEM-correct fix that avoids digging, pipe cutting, and full valve replacement. The double-beaded seal and captive plunger make the repair straightforward in real-world conditions, and the performance improvement is immediate. As long as you verify compatibility and take a few minutes to clean and inspect the valve seat, this diaphragm delivers exactly what it should: a quick, durable return to leak-free operation.