These devices were commonly called "9D" valves, but the new plumbing code doesn't mention this type of device at all; per section 603.5.10, boilers must be protected by either a testable double ...

Backflow Preventer Valves Market Latest Trends, Industry Size and Future Prospects 2030 | Alfa Laval Inc., NIBCO, Zoeller Company PRESS RELEASE Published October 23, 2023 ...

A new building at the Hunts Point sewage plant in the Bronx was built seven months ago without a necessary "backflow preventer" to protect water in the plant's huge boilers from backing up into ...