How do you blow out the sprinkler system using a compressor?

Blowing out a sprinkler system involves closing the mainline sprinkler shutoff valve and attaching the air compressor to the blow out adapter. Blow out the valve in increments of two minutes or less and repeat the procedure up to three times, and then turn off the timer.

Always wear proper eye protection when blowing out a sprinkler system and always turn off the sprinkler zone valve before beginning the procedure. Follow the steps below to clear the sprinkler system.

1. Close the valve

Close the mainline sprinkler shutoff valve.

2. Stop the water pressure

Lessen the water pressure by activating a zone from the timer. Do this to the circuit farthest from the air connection.

3. Attach the compressor

Attach the compressor to the blowout adapter.

4. Set the regulating valve

Set the pressure-regulating valve to 50 psi. Set it to 80 psi for PVC pipes.

5. Turn on the compressor

Turn on the compressor and slowly increase the airflow until the sprinkler heads pop up.

6. Blow out the system for no more than two minutes

To avoid damage to the system, blow out the system for up to two minutes. Leave the timer on until the compressor is shut off.

7. Repeat

Repeat the procedure until only a fine mist appears. Leave one zone on while turning off the compressor.

8. Unhook the compressor

Unhook the compressor and turn the sprinkler timer to the Off position.