Follow OSHA-compliant procedures and manufacturer pressure limits when winterizing an irrigation system with compressed-air blow-out.

Steps

1. Confirm OSHA 29 CFR 1926.302(b) (power-operated hand tools) and the related compressed-air-for-cleaning interpretation, which limits cleaning-purpose air pressure to under 30 psi and requires chip guarding and PPE (ANSI-approved eye protection at minimum) whenever compressed air is used near people — there is no irrigation-specific OSHA blow-out standard, so this general provision is the closest applicable rule.
2. Set blow-out air pressure within manufacturer/pipe-material limits: commonly cited maximums are about 75 psi for PVC pipe and 50 psi for polyethylene pipe, with airflow volume in the 50-125 CFM range.
3. Never blow air through a backflow preventer or pump — blow out zone piping first, then separately drain the backflow device or pump per its own procedure.
4. Keep the air compressor attended at all times during the process and ensure no personnel stand directly over sprinkler heads, valves, or pipe during blow-out due to flying-debris risk.
5. Stop blowing air once a zone is dry — continued airflow through dry pipe can generate frictional heat and damage components.