Backflow Prevention
The drinking water supply is meant to run one way. A backflow preventer is the mechanical guarantee that it does.
What backflow is
Water in a building supply normally flows in one direction because pressure keeps it that way. If that pressure drops or reverses, water that has already been somewhere else can be drawn back into the supply. The two mechanisms have names worth knowing.
| Back-siphonage | Supply pressure falls, often because of a main break or heavy draw nearby, and the resulting suction pulls water backwards |
|---|---|
| Back-pressure | A downstream system is at higher pressure than the supply and pushes its water back into it. Boilers and pumped systems can do this |
Where the city requires protection
New York City's Department of Environmental Protection requires approved backflow prevention on services where there is a recognized hazard to the public supply. In practice that typically covers premises with boilers or chilled water plant, food service establishments, medical and laboratory uses, buildings with fire suppression systems, irrigation connections and a number of other categories. Where a device is required, the city also requires that it be registered and tested annually, with the results filed.
That annual test is a formal, recorded obligation rather than a maintenance suggestion, and for a commercial tenant it is often the thing that turns up during an inspection.
What we do
- Installing and replacing devices where a building or a fit-out needs one
- Repairing devices that fail their test, which is usually fouled or worn internal checks rather than the whole assembly
- Sorting out the drainage a reduced pressure device needs, because these units discharge when they relieve and the discharge has to go somewhere acceptable
- Dealing with the practical side: access, isolation, and how to do it without taking the building's water out for a day
The annual test and the filing that goes with it carry a deadline, and missing it tends to surface during an inspection rather than before one. Where a device on your building is due, we will tell you so directly rather than leave you to find out the hard way.
Restaurants and ground-floor fit-outs
The storefronts along Ninth and Tenth Avenues, through the Meatpacking District and across Chelsea turn over regularly, and a new food-service tenant inherits whatever the last one left. Backflow protection is one of the things that gets discovered late in a fit-out, after the lease is signed and the opening date is set. It is a great deal cheaper to establish what is there at the survey stage. See commercial plumbing.
Need this doing?
Call and describe the problem. You will get the price before anyone starts.