The state layer
New York State's Department of Health publishes "Guidelines for Designing Backflow Prevention Assembly Installations" (1992, a supplement to its 1981 Cross Connection Control Manual), built on AWWA, EPA, and USC guidance. Its installation section is concrete: assemblies "shall be installed with a centerline height from 30 inches to 60 inches above the floor"; a minimum of 12 inches clear above the assembly, 30 inches in front, and 8 inches behind; and 18 inches between an RP relief valve and the floor. Pits are discouraged; where used, they must be watertight with access doors "extending a minimum of 6 inches above grade," drained, and covered deeply enough to prevent freezing. The guide requires that assemblies be installed "to prevent freezing, flooding and mechanical damage" without naming a product.
The 2025 Plumbing Code of New York State (in effect since December 31, 2025) is based on the International Plumbing Code, so outdoor enclosures comply with ASSE 1060 and assemblies in freezing areas are removable by unions or protected from freezing by heat, insulation or both.
What the cities add
New York City DEP requires plans from a licensed PE or RA and approves each installation before a Licensed Master Plumber installs it, with certified testing every 12 months; city assemblies are typically indoors in mechanical rooms. Long Island, Westchester, and the upstate cities typically follow the DOH guide in their own standards; heated enclosures are the usual answer on fire service and on outdoor assemblies upstate, where design lows run well below zero.
What this means for a cover
- Indoors is the New York default for domestic assemblies, and no cover is needed.
- Outdoor domestic RPs downstate (Long Island, Westchester, the Hudson Valley): insulation is a code-named method and a fitted cover on a flowing service carries the winter with heat trace as backup. Mind the DOH clearances; a cover must lift off for the tester.
- Upstate and fire service: heat. The cover is the insulation layer under it.
- Irrigation: Long Island is a major irrigation market, drained by November. Covers for the shoulder seasons; the PVB and small-RP bins.
Market notes
Long Island and the Hudson Valley carry the outdoor volume; the city is indoor. Backflow testers, who are licensed and numerous in New York, are the channel that meets these assemblies most; plumbing houses carry the commercial side. Both order through the distributor program.
Testers and covers
New York licenses backflow testers through the Department of Health and the county programs, and the tester is often the person who sees the outdoor assembly each spring. A cover that lifts straight off for the annual test and closes again at the base fits the clearances the guide asks for without adding a structure the inspector has to approve.