Welcome to the Pressure Regulator Buying Guide! If you’ve made it this far, you’re probably on the right track. In this guide you will learn about pressure regulators; what they do, who needs them, how they work, and what information you’ll need to determine the best device for your system. 


What does a pressure regulator do?


The pressure regulator maintains the pressure within the system and protects against spikes or sudden drops in pressure from the water source. This device ensures the pressure within the system will stay a consistent pressure, thus resulting in optimal performance from the emitting devices.


Please note, various watering devices may specify they are “pressure compensating” however, this is different than pressure regulation. Compensation refers to an emitter consistently disbursing the pre-set flow rate, regardless of small pressure changes, however, pressure compensating emitting devices will not regulate the system pressure. 


Who needs a pressure regulator?


Most if not all, pressurized irrigation systems will require a pressure regulator. An exception to this would be if you are using a gravity system with very low pressure, or very low flow. 


How does a pressure regulator work?


Water flows through the inlet, around the seat and through the t-stem. Water pressure acting on the diaphragm forces the spring to compress, pushing the t-stem toward the seat. The closing of the area between the seat and the t-stem reduces the water pressure on the diaphragm. The balance between the force on the diaphragm and spring resistance establishes the outlet pressure.


Irrigation pressure regulators need outflow and back pressure to regulate the pressure within your irrigation system. With no water flowing through the regulator, the inlet and outlet pressures will measure the same. To verify the pressure maintained in your system, you will need to place a pressure gauge at the end of one of zones, turn the zone on, let it pressurize and once the lines have filled and emitters begin to flow then take the reading. This will reflect the working pressure within your system.


Because of this, a certain amount of pressure (PSI) and flow (GPH/GPM) is required for a pressure regulator to operate.





What factors should be considered when selecting a pressure regulator?


1. Flow rate of the system - Not just the water source


In order for a pressure regulator to operate correctly, a certain flow rate must be met. Not just at the inlet of the regulator, but through the outlet as well. This means your system must meet a certain amount of flow. 


If you need to determine the flow rate of your water source, here is our flow rate calculator. 


To determine the flow rate of your system, you will want to add up the number of emitters and multiply by the emitter flow rate. For instance, if you have 100 emitters with a flow rate of .5 GPH, (100 emitters x .5 GPH each = 50 GPH). You will want to take into consideration the flow rate of your system is 50 GPH. 


To convert from gallons per hour (GPH) to minutes (GPM), simply divide by 60 (minutes). In this example, 50 GPH/ 60 minutes = .833 GPM.


Low flow is typically 6 GPH (.1 GPM) to 420 GPH (7 GPM).


Medium flow is normally 240 GPH (4 GPM) up to 1200 GPH (20 GPM).


High flow is 600 GPH (10 GPM) up to 6000 GPH (100 GPM). 


2. The pressure (PSI) of the water source and PSI requirements of the emitting devices


Checking the pressure of your water source can be done using a simple pressure gauge fitted with the hose thread adapter, here is a link to our selection of Pressure Gauges. Most pressure regulators require at least 5 PSI above the preset pressure in order to regulate the pressure. Meaning if you’re using a 20 PSI regulator, your water source must provide at least 25 PSI. 


3. The system configuration - Thread type and installation


Our pressure regulators are offered in a variety of thread types and sizes including pipe thread (NPT, FPT, MPT) and hose thread (FHT, MHT), in both female (F) and male ends (M), from ½” up to 2” connections. 


None of the pressure regulators we carry are rated for constant pressure. Meaning, these must be installed after any timers or valves in order to ensure that the pressure is relieved. 


When installing a head assembly in a hose bibb system, we recommend the following head assembly order of components:Timer (optional), Backflow Preventer, Filter, Pressure Regulator, 1/2" Swivel adapter or tubing adapter. For more information on head assemblies, check out our “Do I need a head assembly?” article. 


Here is a quick chart of the Pressure Regulators we offer:


Manufacturer/Model

Thread type

Thread size

Flow rate required

Preset & Max PSI

DIG:

3/4" Pipe Thread Adjustable Pressure Regulator (FPT x FPT)

FPT inlet, FPT outlet

¾”

2 GPM - 22 GPM


(120 GPH - 1320 GPH)

125 PSI

Global:

3/4" FHT X 3/4" MPT Pressure Regulator

FHT inlet, MPT outlet

¾”

1 GPM -15 GPM


(60 GPH - 900 GPH)

80 PSI

Hendrickson Bros:

Mini Pressure Regulator

FPT inlet, MPT outlet

½”

0.1 GPM - 4 GPM


6 GPH - 240 GPH

100 PSI

Hendrickson Bros:

3/4" Low Flow Pressure Regulator

FHT inlet, MHT outlet

¾”

1 GPM - 8 GPM


(60 GPH - 480 GPH)

100 PSI

Hendrickson Bros:

3/4" Low Flow Pressure Regulator

FPT inlet, MPT outlet

¾”

1 GPM - 8 GPM


(60 GPH - 480 GPH)

100 PSI

Hendrickson Bros:

Hose Thread Pressure Regulator

FHT inlet, MHT outlet

¾”

.3 GPM - 12 GPM


(20 GPH - 720 GPH)

120 PSI

Senninger:

3/4" Hose Thread Pressure Regulator (PLRG)


FHT inlet, MHT outlet

¾” 

.5 GPM - 7 GPM


(30 GPH - 420 GPH)

10 PSI - 90 PSI

15 PSI - 95 PSI

20 PSI- 100 PSI

25 PSI -105 PSI

30 PSI - 110 PSI

35 PSI - 115 PSI

40 PSI - 120 PSI

Senninger:

3/4" Pipe Thread Pressure Regulator (PRLG)

FPT inlet, MPT outlet

¾”

.5 GPM - 7 GPM


(30 GPH - 420 GPH)

10 PSI - 90 PSI

15 PSI - 95 PSI

20 PSI- 100 PSI

25 PSI -105 PSI

30 PSI - 110 PSI

35 PSI - 115 PSI

40 PSI - 120 PSI

Senninger:

3/4" FPT x 3/4" MHT Pressure Regulator (PRLG)

FPT inlet, MHT outlet

¾”

.5 GPM - 7 GPM


(30 GPH - 420 GPH)

10 PSI - 90 PSI

15 PSI - 95 PSI

20 PSI- 100 PSI

25 PSI -105 PSI

Senninger:

Pressure-Master 3/4" FPT Regulator - Medium Flow (PMR) 6 PSI - 10 PSI


FPT inlet, FPT outlet

¾”

4 - 16 GPM


(240 GPH - 960 GPH)

6 PSI - 80 PSI

10 PSI - 90 PSI


Senninger:

Pressure-Master 3/4" FPT Regulator - Medium Flow (PMR) 12 PSI - 50 PSI

FPT inlet, FPT outlet

¾”

2 GPM - 20 GPH


(120 GPH - 1200 GPH)

12 PSI - 90 PSI

15 PSI - 95 PSI

20 PSI - 100 PSI

25 PSI -105 PSI

30 PSI - 110 PSI

35 PSI - 115 PSI

40 PSI - 120 PSI

50 PSI - 130 PSI

Senninger:

Pressure-Master 1" FPT Regulator - Medium Flow (PMR)

FPT inlet, FPT outlet

1”

2 GPM - 20 GPH


(120 GPH - 1200 GPH)

12 PSI - 90 PSI

25 PSI -105 PSI

30 PSI - 110 PSI

35 PSI - 115 PSI

40 PSI - 120 PSI

Senninger:

FPT x FPT Pressure Regulator - High Flow (PR-HF)


FPT inlet, FPT outlet

1-¼” inlet, 

1 or 1-¼” outlet

10 GPM - 32 GPM


(600 GPH - 1920 GPH)

10 PSI - 60 PSI

15 PSI - 80 PSI

20 PSI - 100 PSI

25 PSI - 100 PSI

30 PSI - 100 PSI

40 PSI - 100 PSI

50 PSI - 100 PSI

Senninger: 

2" Ultra High Flow Pressure Regulator (PRU)

FPT inlet, FPT outlet

2”

20 GPM - 100 GPM


(1200 GPH - 6000 GPH)

10 PSI - 90 PSI

15 PSI - 95 PSI

20 PSI- 100 PSI

25 PSI -105 PSI

30 PSI - 110 PSI

40 PSI - 120 PSI

60 PSI - 140 PSI


2-in-1 Pressure regulators:


In addition to regulating the pressure within the system, various manufacturers have also included an added filter element to help eliminate or reduce the need for additional system components. Various manufacturers (such as Aqualine and Hydro-rain) make 2-in-1 filter and pressure regulator combinations. These combination devices are great as they save money and space in your system assembly. 


Here is a quick chart:


Manufacturer/Model

Thread type

Thread size

Flow rate required

Filtration level

Preset PSI

Max PSI

Aqualine:

Pressure Regulating Plastic Y Filter

MPT inlet, MPT outlet

¾”

.2 GPM - 5 GPM


(12 GPH - 300 GPH)

200 Mesh

15 PSI

25 PSI

45 PSI

120 PSI

Aqualine:

Pressure Regulating Plastic Y Filter

MPT inlet, MPT outlet

1”

.2 GPM - 10 GPM


(12 GPH - 600 GPH)

200 Mesh

15 PSI

25 PSI

45 PSI

120 PSI

Hydro-Rain:

Filter and 30 PSI Regulator in One

MPT inlet, MPT outlet

¾” or 1” inlet, 1” outlet

.1 GPM - 5 GPM


(6 GPH - 300 GPH)

200 Mesh

30 PSI

80 PSI

Hydro-Rain:

Blu-Lock 2-in-1 Drip Regulator & Filter

1” Blu-lock inlet, 1” MPT outlet

1”

.1 GPM - 5 GPM


(6 GPH - 300 GPH)

200 Mesh

30 PSI

80 PSI

Hydro-Rain:

PVC-Lock 2 in 1 Drip Regulator & Filter

1” PVC-lock inlet, 1” MPT

1”

.1 GPM - 5 GPM


(6 GPH - 300 GPH)

200 Mesh

30 PSI

80 PSI


Other regulators and pressure devices:


There are some system configurations where a pressure regulator is best installed at the valve. In this case, the Irritrol Omnireg Adjustable Pressure Regulator is a great item to use (please note this is only compatible with Irritrol Valves).  This device allows the user to precisely set and maintain the exact downstream pressure required for any application. It is adjustable from 5 PSI up to 100 PSI, by simply turning the easy to use dial to the desired setting.


Finally, the last device we will cover in this article are the pressure reducing valves. Pressure reducing valves are different than pressure regulators. One of the biggest differences with the reducers we carry, is that they are able to withstand constant pressure, unlike pressure regulators.  



Manufacturer/Model

Thread type

Thread size

Flow rate required

Preset PSI

Max PSI

Irritrol:

Omnireg Adjustable Pressure Regulator 

Drop-in installation, only requires two screws to secure (Directly installed on valve)

1 GPM - 300 GPM


(60 GPH - 18000 GPH)

Adjustable; 5 - 100 PSI

200 PSI

Aqualine:

Lead Free PRV3 Brass Pressure Reducer

FPT x Union connections

 ¾”

1 GPM - 30 GPM


(60 GPH - 1800 GPH)

Adjustable from 25 - 75 PSI, pre-set to 50 PSI

300 PSI

Aqualine:

Lead Free PRV3 Brass Pressure Reducer

FPT x Union connections

 1”

1 GPM- 50 GPM


(60 GPH - 3000 GPH)

Adjustable from 25 - 75 PSI, pre-set to 50 PSI

300 PSI

Aqualine:

Double Union PRV4 Lead Free Brass Pressure Reducer

Double union connections

 ¾”

1 GPM - 30 GPM


(60 GPH - 1800 GPH)

Adjustable from 25 - 75 PSI, pre-set to 50 PSI

300 PSI

Aqualine:

Double Union PRV4 Lead Free Brass Pressure Reducer

Double union connections

 1”, 1-¼”, 1-½”, 2”

1 GPM- 50 GPM


(60 GPH - 3000 GPH)

Adjustable from 25 - 75 PSI, pre-set to 50 PSI

300 PSI

Aqualine:

Lead Free Brass PRV6 Pressure Reducer

Solder union x FPT connections

¾” or 1”

1 GPM - 30 GPM


(60 GPH - 1800 GPH)

Adjustable from 25 - 75 PSI, pre-set to 50 PSI

300 PSI