Pressure Regulator Buying Guide
What exactly is a pressure regulator, and why do you need one? This guide is here to answer those questions.
A pressure regulator is a device placed on your system that reduces the incoming water pressure to a safe range for your drip products. The pressure regulator maintains the pressure within the system, keeping it at an optimal pressure and protecting the system against surges.
Who needs pressure regulation? Almost everyone will need a pressure regulator on their system. Most residential water sources, such as a city or private well, have a starting pressure of roughly 40-90 PSI. That means, for most drip systems, you will need some type of pressure regulator. The exception would be if you are using a low-pressure gravity system as your water source, or if you are using a high-pressure product such as foggers or rotors. This chart shows the safe pressure range for various products:
|
Emission Device |
Minimum Pressure Required |
Maximum Pressure Rating |
|
Drip Tape |
4 PSI |
15 PSI |
|
1/4" Soaker Dripline |
2 PSI |
30 PSI |
|
½" Emitter Tubing |
10 PSI |
50 PSI |
|
Basic Drip Emitter |
4 PSI (varies) |
30 PSI |
|
Pressure Compensating Emitter |
10 PSI (varies) |
50 PSI |
|
Misters |
20 PSI |
40 PSI (varies) |
|
Foggers |
40 PSI |
100 PSI |
|
Micro Sprinklers |
15 PSI |
50 PSI (varies) |
|
Spray Nozzles, Rotors |
25 PSI |
50 PSI |
As you can see, some products have a very wide range of operating pressure while others have a much smaller range. Some products, such as a Rotor sprinkler or a fogger, operate at very high pressures and may not need regulation depending on your water source and starting pressure. Other products, such as drip tape, have a very small and low-pressure range and should be used with a pressure regulator.
How does a regulator work? Water flows into the regulator, around the seat, and through the t-stem. Water pressure on the diaphragm forces the spring to compress, which causes the t-stem to be pushed towards the seat. The closing of the area between the seat and the t-stem reduces the pressure on the diaphragm. The balance between the water force on the diaphragm and the spring resistance sets the outlet pressure. For this to take place, a certain amount of flow needs to be used in your system. Simply having water flow through the system will not activate a pressure regulator and create the required pressure on the diaphragm to reduce the outlet pressure.
For a regulator to function properly and reduce the incoming water pressure, it will require a certain amount of flow from the system. Each regulator will have a different minimum flow rate required to reduce pressure in the system and a maximum flow rate that it allows. This flow rate differs from the available flow rate from your water source. It is the amount of water your system is outputting. You can find that flow rate by counting the number of emitters or emission devices on your system then multiply that number by the flow rate per device. For example, say you have 85 emitters, each using 1 GPH. That means you are using 85 gallons per hour in your system. Divide that number by 60 to get your gallons per minute. 85/60=1.416 GPM. Use the table below to choose a regulator that would be the correct size based on your flow rate.
|
Pressure Regulator |
Available Outlet Pressure |
Minimum Flow Required |
Maximum Flow Rate |
Maximum Inlet Pressure |
Thread Type and Size |
|
10, 20, 30, 40 PSI |
0.5 GPM |
7 GPM |
90 PSI |
3/4" Hose |
|
|
12, 20, 30 PSI |
0.5 GPM |
8 GPM |
90 PSI |
3/4" Hose |
|
|
30 PSI |
0.5 GPM |
12 GPM |
150 PSI |
3/4" Hose |
|
|
12, 30 PSI |
2 GPM |
20 GPM |
90 PSI |
3/4" Pipe x 3/4" Hose |
|
|
12, 20, 35, 50 PSI |
5.5 GPM |
17.6 GPM |
120 PSI |
3/4" Pipe |
|
|
10, 30 PSI |
10 GPM |
32 GPM |
90 PSI |
1 1/4" x 1" Pipe |
|
|
12, 35 PSI |
11 GPM |
35 GPM |
120 PSI |
1 ½" Pipe |
|
|
12, 35 PSI |
22 GPM |
70 GPM |
145 PSI |
2" Pipe |
A pressure regulator is placed on your system after your timer or valve that shuts the water off when you are finished with a watering cycle. The regulator should also be placed after your filter so that only clean water is going through your regulator. This will prevent anything from clogging up the inside components and causing damage to your regulator.
For multiple zone systems, you can use a pressure limit valve, which is rated for constant pressure, and can be placed before your valves. This allows you to only need one limit valve instead of multiple pressure regulators. A limit valve works a little differently than a regulator. A regulator requires flow to start reducing pressure, but with a limit valve, it holds the system pressure within 10-15 PSI of the set pressure even when the flow stops. This is because the limit valve has a rubber seat where the regulator does not. DripWorks carries a Senninger Limit Valve in the below options:
|
Part Number |
Pressure Setting |
Flow Range |
Thread Size and Type |
|
10, 20, 30, 40, 50 PSI |
0.5-18 GPM |
3/4" Female Pipe Thread |
|
|
30 PSI |
0.5-18 GPM |
1" Female Pipe Thread |
After reading this guide, you should have the information to choose a pressure regulator for your system's needs. DripWorks has a wonderful support staff available on chat or by phone Monday through Friday from 8 am-4 pm PST to answer any other questions you may have. Our number is 1-800-522-3747 to reach customer service.