Winterizing your sprinkler system before the freeze

Water trapped in irrigation pipes through a hard freeze expands by about 9% and splits whatever holds it. Cracked PVC, ruptured backflow preventer, broken zone valves: none of it shows up until spring start-up, and by then it is a four-figure repair. The fix is a one-afternoon procedure with the right supplies on hand before the first cold snap.

The full how-to is in our step-by-step winterization guide for Hunter sprinkler systems, which covers manual-drain and compressed-air blow-out methods with Hunter’s published PSI limits (80 PSI max for PVC pipe, 50 PSI max for polyethylene). Pick the supplies you need below; the three buckets map onto the procedure’s main steps.

What’s in this category

• Insulated backflow bags. The most freeze-sensitive component sits above grade; bag it after draining. Small (BFA1HBBG) for residential PVBs and double-checks; 24"×24" or 34"×24" for larger residential and light-commercial devices.
• Winter plugs (#6 through #12). Cap exposed pipe ends during the manual-drain procedure. Mixed-size sets cover most residential systems.
• Drain valves. Auto-drain valves for the manual-drain method, plus Hunter drain check valves for retrofit or replacement.

Compressed-air blow-out also needs an NPT-to-air-coupler fitting sized to your blow-out port (typically 3/4" or 1" male NPT). Hardware stores carry these; Total Sprinkler does not currently stock dedicated blow-out adapters.