VR20 3/4" Vacuum Relief Valve with Dust Cover

Features:Prevents internal vacuum conditions: Guards against siphonage, burnt-out heaters, and collapsing of storage tanks and negative pressure.Opens quickly in emergencies: Opens on a one-inch mercury vacuum.Listed by CSA: Inspector friendly, peace of mind.Every valve is tested for performance before shipping: Specify and install with confidenceApplications:For protection of commercial hot water supply systems and pressure vessels against negative pressureThe Cash Acme VR20 Vacuum Relief Valve is designed to protect hot water supply systems and pressure vessels against negative pressure. It is especially well-suited for many domestic and commercial systems.It works by preventing internal vacuum conditions that could result in burned-out heaters and collapsed storage tanks - especially copper. Installed on the cold water supply line, the Cash Acme VR20 closes tightly under pressure and opens at a 1" mercury vacuum. The atmosphere admitted to the system breaks the vacuum, preventing the collapse of the storage tank. It is recommended that the VR20 be installed in an upright position.The VR20 also features a low-profile design with a slotted vent hole. Circular dust protects the vent hole cover approximately 1.75" in diameter. This valve features an all-brass body and body cap, a heat-resistant silicone seat disc, an integral body seat, and brass internal working parts.