Winterizing Sprinkler System with a 30-Gallon Air Compressor

A 30-gallon compressor can blow out a 6-zone, 1" mainline system—it just takes patience and a zone-by-zone approach.

Procedure

1. Pressurize tank to max (typically 120–150 PSI).
2. Open one zone valve manually at the controller or bleed screw.
3. Run until pressure drops to ~40 PSI, then close valve.
4. Wait for tank to rebuild pressure.
5. Repeat for that zone 2–3 times until only mist exits heads.
6. Move to next zone. Repeat for all 6 zones.

Tips

• Start with the zone farthest from the compressor connection.
• Don't exceed 50 PSI in the lines—use a regulator on the compressor outlet.
• Open drain valves/backflow preventer test cocks after blowing out.
• Expect 20–30 minutes total. It's slower than a 60-gallon tank but effective.

Small tanks work fine for residential systems if you cycle zones. The key is letting the compressor recover between bursts.