Febco 765 PVB Backflow Preventer with Union End Ball Valves
Series 765 Pressure Vacuum Breakers are designed to be installed to provide protection against back siphonage of toxic or non-toxic liquids. They feature a durable bronze body and a check valve and air opening port in one assembly. Maximum Working Pressure: 150psi (10.3 bar).
- All bronze body for durability. One check valve and an air opening port in one assembly.
- Lightweight poppet seals air opening under minimum flow conditions.
- Simple service procedures. All internal parts serviceable in line from the top of the unit.
- Designed for minimum head loss.
- Engineered plastic bonnet protect valve bodies from freeze damage.
- Optional union end ball valves for easy removal and ultimate freeze protection.
- End Connections - NPT ANSI/ASME B1.20.1
over 2 years ago
over 2 years ago
I presume I still need to purchase two (inlet/outlet) 1" brass unions, and just not use one of the fittings that come as part of the union, substituting the one I remove with the one that is part of this unit. Is this correct?
Thanks in advance.
1. Shut off the water to the sprinkler system (turn the bottom gate valve so that the handle is horizontal (as shown in the picture)
2. Manually turn on the sprinkler system so that the solenoids will open and the water will drain from the output pipe and valve from this preventer (the upper gate valve and pipe attached to it). This will empty water out of the portion of the sprinkler pipe that is above ground.
3. Once this is done, turn the top gate valve so that the handle is vertical (as shown in the picture). This will keep the pipe clear from anything that may come in.
4. Take a screw driver and open the two little drain valves at the upper right on the picture -- this will drain any water that is still in the preventer bowl. Leave these open.
5. Now, there should be no more water in and around the preventer to freeze, expand, and crack the preventer. If you are still concerned, you can unscrew the union joints and remove the entire preventer assembly, leaving the union ball valve ends in place in shut off position, and put it somewhere it will not freeze. However, if you have properly drained the water, that should be unnecessary -- but you may be worried about a buildup of condensation (the small screwdriver openings should prevent this) or are tired of buying new backflow preventers, are worried that the plastic parts will become brittle in the cold, or otherwise just want to play it safe.
To un-winterize the system, just reverse all the steps until you re-open the gate valve at the bottom and re-charge the system with water. Do this slowly, or the onrush of water may crack the plastic parts inside, which may have become brittle.