Senninger Low Flow Regulator

Build your low-flow drip irrigation head assembly safely.

Step 1: Prep the Inlet Threads
Because the inlet utilizes standard Pipe Threads (FPT), you must apply 3 to 4 wraps of Teflon tape to the 3/4" Male PVC fitting or pipe-threaded filter you will be threading into the regulator. Do not use liquid pipe dope.

Step 2: Connect the Inlet
Thread the PVC fitting or pipe-threaded filter from your upstream valve into the 3/4" FPT inlet of the Senninger regulator. Crucial: Look closely at the body and ensure the directional flow arrow points downstream toward your fields.

Step 3: Connect the Outlet
Because the outlet utilizes Hose Threads (MHT), do NOT use Teflon tape on it. Simply thread a Female Hose Thread (FHT) tubing adapter directly onto the regulator. The adapter's internal rubber washer will create the watertight seal.

Step 4: Pressurize and Test
Turn on the irrigation valve. The internal diaphragm will instantly drop the pressure passing through the unit to a safe 12 PSI, safeguarding your downstream drip tubing.

Is 12 PSI the correct pressure for my system?
The PRSLPH12 (12 PSI) model is designed specifically for thin-walled Drip Tape (like 6 mil or 8 mil) which can easily rupture at higher pressures.

If you are using thicker 1/2" poly tubing, standard punch-in drip emitters, or micro-sprinklers, you will likely need a higher pressure regulator (such as 25 PSI or 30 PSI) to ensure proper operation.

What happens if my flow is less than 0.5 GPM?
Pressure regulators require a certain volume of water passing through them to accurately engage the internal diaphragm. If your zone draws less than 0.5 Gallons Per Minute (30 GPH), this regulator will not function properly.

In extremely low-flow scenarios, the pressure will not drop accurately, potentially allowing dangerously high pressure into your drip lines. Always ensure your zone has enough emitters to meet the 30 GPH minimum.

Can I leave this regulator under constant pressure?
No, Senninger pressure regulators are not rated for constant pressure. They must be installed after an automated timer or irrigation valve so they only hold pressure when the system is actively watering.

Installing them upstream of a closed valve leaves the plastic housing pressurized 24/7, which can eventually cause it to stress, crack, or leak.

How should I winterize my Senninger pressure regulator?
Before freezing temperatures arrive, you must completely blow out or drain all water from your irrigation head assembly.

Any water left trapped inside the regulator's body will expand as it turns to ice, which will permanently destroy the internal diaphragm and crack the plastic housing. If you cannot blow out the lines, unthread the unit and store it indoors.