The FEBCO 765 Pressure Vacuum Breaker (PVB) protects your home's potable water supply from back-siphonage of irrigation water, fertilizers, and other contaminants. Installed downstream of your water source and at least 12 inches above the highest sprinkler head or outlet, this all-bronze assembly combines a spring-loaded check valve and air-opening port in one compact unit. Available in 3/4" and 1" sizes, it's rated for a maximum working pressure of 150 psi (10.3 bar). This model includes a built-in freeze sensor that detects when temperatures near freezing; note that the sensor is passive out of the box, so an add-on BMS/IMS connection kit (available separately from FEBCO) is required to activate freeze alerts. All internal parts are serviceable in line from the top of the unit. Install the valve only in the vertical, upright orientation shown in the manufacturer's instructions. After installation, fill the assembly with water, open the inlet valve to pressurize the unit, then slowly open the outlet valve to fill the downstream line.
Key features of the FEBCO 765
The FEBCO 765 is designed to prevent back-siphonage and maintain potable water safety. It is an all-bronze assembly with a spring-loaded check valve and an air-opening port built into a compact unit. The 3/4" and 1" sizes accommodate common residential irrigation systems and withstand typical working pressures up to 150 psi (10.3 bar). A notable enhancement is the built-in freeze sensor that, when paired with a separate BMS/IMS kit, can provide freeze alerts to help protect the system during cold weather. Serviceability is straightforward, with all internal parts accessible in line from the top. Proper installation requires a vertical upright orientation, ensuring reliable operation and ease of maintenance. After securing the valve, the recommended procedure is to fill the assembly with water, pressurize the unit by opening the inlet valve, and then gradually fill the downstream line by opening the outlet valve.
Installation and operation best practices
Install the valve only in the vertical, upright orientation shown in the manufacturer's instructions. After installation, fill the assembly with water, open the inlet valve to pressurize the unit, then slowly open the outlet valve to fill the downstream line. Not by itself. No.
Achieving the picturesque yard requires a properly functioning sprinkler system. August offers a prime time to refresh your garden beds before temperatures drop. Introducing the Blow Out Bonnet or BOB for short. With this tool you will be able to save on average 15 minutes per residential winterization by opening up to 6 zones all at once. Essentially cutting your time per job in half. BOB will allow you to almost double productivity while keeping labor costs the same. Enabling you to get another 5-10 jobs done per day.
Blow Out Bonnet (BOB) and winterization efficiency
Let me explain how it works. The Blow Out Bonnet replaces the factory bonnet during winterization. Just simply remove the factory poppet and bonnet and screw BOB in its place. BOB has a 3/4" threaded hole in the top allowing you to use a 3/4" hose. This will provide 6 times the volume of air versus a 1/4" test port and 9 times the volume of air the 1/8" test port can supply. For maximum efficiency we recommend a pull behind 185 cfm compressor with ¾ “ hose and a setting of 75psi. Contractors or homeowners with a smaller compressor and 3/8 or ½ hose can still use our adapters however the lower volume may only blowout 1 or 2 zones at a time. A ¾ “ hose also provides for more consistent air pressure delivery. The air pressure loss on 100’ of ¾ “ hose is only 6 psi compared to over 40 psi loss on a 1/2 “ hose. BOB allows you to still winterize your customers system even if the factory poppet and bonnet are broken, frozen, damaged or missing! No more second trips out to the same property.
Practical setup and operation details
BOB adapters can make the winterization contactless. If the water is off and the valves are accessible in the valve box there is no need for the customer to be home or go inside their basement or garage. BOB allows for a visual inspection of the pvb which can find problems early. ⚠️ Warning This post is more than 10 years old. I do not delete posts, because even old information is still useful, but please know that some material on this page may be outdated or incorrect.
Further practical notes from enthusiast experiences emphasize that the original components of irrigation systems often remain robust, and winterization remains critical in colder climates. A common approach uses a compressor and a piggy-back tank to extend airflow, enabling efficient blowing out of multiple zones. For example, a setup may involve connecting the air compressor to the FEBCO valve via a tee, using a piggy-back tank to boost CFM, and carefully pulsing air to clear irrigation lines without damage. The general principle is to alternate opening and closing valves across zones, monitoring the release of air and water until the line is cleared of water.
Safety and maintenance considerations
Ensure proper pressures and procedural steps to avoid damage: use a regulator to maintain appropriate psi, keep the system upright during operation, and follow the manufacturer’s guidance for fill and pressurization. Regular inspections of the PVB can reveal leaks, corrosion, or improper seating of the check valve, which can compromise backflow protection. The freeze sensor feature (with optional BMS/IMS) adds another layer of safety by alerting to freezing conditions that could damage components or allow contamination if not addressed promptly.
When to consider upgrading or expanding
For larger or more complex irrigation systems, upgrading to the FEBCO 765 with a compatible BMS/IMS integration may offer enhanced monitoring and protection. The combination of a robust, serviceable design and updatable sensor capabilities makes it a practical choice for homeowners seeking reliable backflow prevention and proactive weather-related alerts.
