Hunter HFR Filter Pressure Regulating ¾” Inlet 25 PSI

Build your drip irrigation head assembly safely and quickly.

Step 1: Prep the Threads
Because this unit utilizes Male Pipe Threads (MPT), you must apply 2 to 3 wraps of Teflon tape to both the inlet and outlet threads to ensure a watertight seal. Do not use liquid pipe dope.

Step 2: Attach to Your Valve
Thread the inlet of the Hunter HFR combo unit directly into the downstream side (outlet) of your automated 3/4" irrigation valve. Ensure the directional flow arrow on the body points downstream toward your garden.

Step 3: Add a Tubing Adapter
Thread a 3/4" Female Pipe Thread (FPT) tubing adapter or PVC fitting onto the outlet of the combo unit to easily transition into your poly mainline or drip tape header.

Step 4: Routine Cleaning
Periodically (once a month) turn off the water supply, unscrew the filter canister cap, carefully slide the stainless steel screen out, and rinse it under clean water to remove trapped sediment.

Can I leave this combo unit under constant pressure?
No, the Hunter HFR-075-25 is not rated for constant pressure. It must be installed after your automated timer or irrigation valve so it only holds pressure when the system is actively watering.

Installing it before the valve leaves it pressurized 24/7, which can eventually cause the canister body to stretch, crack, or leak over time.

What does the 150-mesh screen do?
The 150-mesh screen is a fine stainless steel filter (equivalent to 100 microns) designed to trap particles of dirt, sand, and rust. It provides excellent protection, preventing your drip emitters and micro-sprays from clogging.

Regular cleaning of this screen ensures your system maintains its full 0.5-15 GPM flow capacity without restricting water to your plants.

Will this work if my water flow is less than 0.5 GPM?
For the internal pressure regulator to accurately step the pressure down to 25 PSI, the system requires a minimum flow of 0.5 Gallons Per Minute (30 GPH).

If your drip zone uses very few emitters and draws less than 0.5 GPM, the regulator may not engage correctly, allowing higher pressure water into your drip lines. This is generally only a concern for exceedingly small patio setups.

How should I prepare my Hunter filter for spring watering?
As you set up your system for spring, unscrew the canister and inspect the stainless steel screen for any damage or scale buildup from the previous year.

Clean it thoroughly with a soft brush, ensure the O-ring inside the cap is properly seated, and hand-tighten the canister back on. Turn the system on to flush the line once before reattaching your downstream drip tubing.