Water pressure determines how far apart your sprinkler heads can be spaced to work properly, and it can also determine which type of sprinkler head is a better choice for your application. Here’s a quick explanation of water pressure – what it is and how the effect it can have on the sprinkler system you choose:
How is pressure measured?
Water pressure is measured in pounds per square inch – also called psi. The average water pressure for most homes and businesses is between 30 psi and 50 psi; most sprinkler systems are designed to use pressures of around 30 psi. You can measure the water pressure at your site with a flow meter or water gauge attached to an outdoor faucet. When determining your sprinkler needs, use the lowest pressure reading to ensure the best functionality.
- Spray heads and rotators. Most spray and rotator heads are designed to work their best at about 30 psi. When pressure is lower, the watering radius will be reduced, so you may need to place your heads closer together to get the coverage you need. Higher pressures – those above about 40 psi – will cause the head to mist or fog. Most systems have adjustment valves to help control misting. Pressure regulators installed along the main line can also be used.
- Rotors. Rotors are designed to work best at pressures exceeding 30 psi. If your water pressure is already high, a rotor is a good choice for you; if your pressure is low or average and you need a rotor to water your landscape effectively, you can use a boost pump to increase pressure or adjust the spacing of your rotor heads to help make them more efficient.
- Drip heads (also called drip emitters). These heads are designed to work best at about 20 psi; high pressures – typically those exceeding 40 psi or 45 psi, but sometimes lower – can cause emitters to break apart.