I have a Febco 765 sprinkler backflow regulator. How can I find out what size it is?

measure the intake side of the backflow preventer. i believe there is also a number stamped on the device. that is a fairly pricey item, you will have to go to an irrigation supplier for that item. good luck. also to prevent that from happening again, you can purchase insulated covers that cover them or wrap with insulated tape. if you only need parts, the supplier should have those too, call and make sure they are a febco dealer.

Hello, I'm no expert in this arena, but I have the same system you're referring to. The Febco 765-1 is actually a PVB (pressure vacuum breaker) that's used to protect your water supply from your sprinkler system in the event of a backflow. Anyway, it sounds like you're wondering how to "turn-on" your system after winter? Here are the steps I go through each spring: 1) Close the two pet-cocks (little openings that can be opened/closed by screws on the side of your Febco 765-1 PVB. Since your system is "turned off" you can verify they're closed by looking in the holes as you turn the screws. 2) Close your main drain in your system. This is usually a spicket somewhere underground in the lowest part of your yard. 3) Turn on the main water source to your sprinkler system. Mine is in a closet in my basement next to the wall where the Febco 765-1 is outside. If you're not sure where this is, just follow the pipe that leads from your Febco 765-1 into your house and start hunting. 4) Slowly open the two valves connected to each side of the Febco 765-1 to allow water to flow into your whole sprinkler system and check for any leaks. If the Febco 765-1 is leaking consistently (I think a minor amount for a short time is fine if memory serves me right...) or either of the valves connected to either side of the Febco 765-1 is leaking you likely had some freeze damage and will need some repair.