Fall is here, and for irrigation professionals, that means one thing: pressure vacuum breakers (PVBs) are about to be put to the test. Turn on the main valve, and suddenly water is gushing where it shouldn’t be. It’s frustrating for your customers and a headache for you.
The good news? Most PVB leaks are preventable with a little foresight and routine maintenance. By understanding why PVBs fail and taking proactive steps, you can help your customers avoid costly repairs and enjoy a smooth, leak-free irrigation season.
Understanding the root causes of PVB leaks can help in prevention:
- Natural Wear Over Time
Components like O-ring gaskets, poppets, and bonnets can degrade with repeated pressure cycles, leading to leaks. Regular inspection and timely replacement of these parts can prevent issues.
- Winter Freeze Damage
Freezing temperatures can cause water left inside the PVB to expand, cracking the brass body or damaging internal components. Even when drained, backflow preventers exposed to freezing air can suffer component damage.
- Dirt and Debris
Small particles can disrupt the poppet’s seal. Encourage customers to keep their valves clean and check for debris, especially after seasonal changes or construction nearby.
- Aging Seals
Poppet seals naturally lose elasticity over time. A worn seal can often be replaced in just 15 minutes, but if the valve is older, a full replacement may be the better choice.
Proactive Steps to Prevent Leaks
Taking preventive measures can save time and resources:
- Winterize Irrigation Lines: Blow out water from underground lines using compressed air and close the isolation valve. This prevents freezing damage and reduces stress on the PVB.
- Install a Schrader Valve: Adding a small air valve between the PVB and isolation valve helps relieve pressure and minimizes leak risk. These valves can be installed using a tee fitting.
- Use Protective Covers or Backflow Blankets: Extra insulation during freezing months protects the valve from cracking and poppet damage. Products like foam pipe insulation or specialized backflow covers can be effective.
- Consider Freeze Relief Valves: Devices like the Zurn ZWFR Freeze Relief Valve automatically open at 35°F to discharge near-freezing water, drawing warmer supply water through the valve until closing when the temperature reaches 40°F. This can prevent damage from sudden or unexpected freezes.
Keep It Legal and Safe
PVBs aren’t just a convenience, they’re required by local building codes to prevent backflow contamination. Remind customers that proper installation and maintenance are essential for compliance and safe irrigation.
By staying proactive, educating customers, and using preventative tools, irrigation systems can stay leak-free and reliable, helping avoid unexpected issues when spring arrives.