Double check assemblies shall consist of two independent “Y” configured check valves. Checks shall be of the spring loaded, center stem guided type. All internal metal parts included in the check assemblies shall be of Series 300 stainless steel, and shall not contain any dissimilar metals. Elastomeric seat disc must be reversible, seat rings shall be B-61 bronze, or Series 300 stainless steel, bolted to the valve bodies incorporating an “O” ring seal to facilitate ease of field removal and replacement.
The check assembly shall be guided at the seat ring and at the cover by replaceable non-corrosive bushings to assure positive check seating. Head loss through the assembly shall not exceed 5.5 PSI at velocities from zero up to and including 7.5 FPS. Flow curves shall be documented by independent laboratory testing.
The assembly shall include flanged, full port resilient wedge shut-off valves and four vandal resistant full port ball valve testcocks, considered integral to the assembly. Assemblies must be factory assembled and backflow tested.
All double check valve assemblies shall be constructed so all internal parts, including seat rings, can be serviced without removing the device from the line.
- Prevents contamination of potable water by backflow from the fire protection system and detects leaks or unauthorized water use at all flow rates.
- By-pass line has water meter in series with an
approved double check valve.
- Simple service proceedures. All internal parts serviceable
3″, 4″, 6″, 8″, 10″