Protect your irrigation mainline from damaging pressure spikes and vacuum suction with the Hunter Air/Vacuum Relief Valve (3/4" MPT). Designed for both commercial and residential applications, this heavy-duty, corrosion-resistant valve acts as the respiratory system for your irrigation zones, allowing air to escape during startup and re-enter during shutdown.
When a watering cycle begins, trapped air is rapidly expelled from the high points of your system without premature closure, eliminating the violent "water hammer" effect that can blow out fittings. When the cycle ends, the AVR075 valve instantly opens to break the vacuum seal inside the pipe. This crucial function prevents your system from sucking mud, dirt, and bacteria backward through your drip emitters, keeping your lines clean and flowing freely.
Detailed specifications for system planning.
| Specification | Details |
|---|---|
| Connection Size | 3/4" MPT (Male Pipe Thread) |
| Maximum Operating Pressure | Up to 80 PSI |
| Material | UV-Protected, Non-Corrosive Plastic |
| MPN | AVR075 |
| Brand | Hunter Industries |
Follow these steps to securely integrate the air/vacuum relief valve into your system.
Step 1: Identify High Points
Locate the highest physical elevation point in your drip irrigation zone. Air naturally rises, so the valve must be placed here to effectively vent trapped air pockets.
Step 2: Install a T-Fitting
Cut your mainline tubing and install a compatible PVC or poly tee fitting that features a 3/4" Female Pipe Thread (FPT) port facing upward.
Step 3: Apply Thread Sealant
Wrap Teflon tape 2-3 times around the 3/4" Male Pipe Threads (MPT) of the Hunter valve to ensure a watertight seal.
Step 4: Thread and Mount Vertically
Thread the Hunter valve into the FPT port. Hand-tighten until snug. Crucial: Ensure the valve is positioned perfectly vertical; the internal float will not seal correctly if mounted at an angle or horizontally.
Why is the Hunter Air/Vacuum Relief Valve important during my spring system startup?
During spring startup, the Hunter Air/Vacuum Relief Valve safely releases trapped air from empty pipes as they fill with water. This prevents violent water hammer and pressure spikes that can blow out fittings and damage your system.
After sitting dry all winter, your lines are completely full of air. Pushing a wall of water into that air creates immense shockwaves unless it is properly vented at the high points.
How does the Hunter AVR075 valve prevent dirt from clogging my emitters?
When your system shuts off, the Hunter AVR075 valve opens to allow air into the mainline. This breaks the vacuum seal, preventing the system from sucking dirt and mud backward through your drip emitters.
Without this valve, gravity pulls water down the pipe, creating a vacuum at the top of the hill. This suction can easily pull wet soil directly into your dripline, ruining your emitters.
Where should I install the 3/4" Hunter Air/Vacuum Relief Valve in my system?
You should install the 3/4" Hunter Air/Vacuum Relief Valve at the highest elevation points of your irrigation mainline. Air naturally rises to these high points, making it the most effective location for safe venting.
For very long runs or undulating terrain, you may need to install multiple valves at each significant crest to ensure the entire zone is protected from water hammer.
What thread type does the Hunter Air/Vacuum Relief Valve use?
The Hunter Air/Vacuum Relief Valve features a 3/4-inch Male Pipe Thread (MPT). You will need a compatible 3/4-inch Female Pipe Thread (FPT) PVC or poly adapter to install it into your drip tubing.
Do not attempt to thread this directly onto a standard outdoor garden hose faucet, as hose threads and pipe threads are incompatible and will leak.
Please note the requirements for this unit:
Ensure your mainline is built correctly with these recommended components:
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