Double Check Valve Testing in Shell Knob, MO
A double check valve assembly, or DCVA, has two independent spring-loaded checks between two resilient-seated shutoffs and four test cocks. It is approved for low-hazard connections, so you see it on many fire lines, apartment services and some irrigation systems.
The tester bleeds and reads each check separately. Each one has to hold a differential of at least 1.0 psid. If a check reads lower, the cause is usually a worn rubber disc, a weak spring or debris across the seat.
Unlike an RPZ, a DCVA can be installed in a pit or vault in many jurisdictions, which brings its own problems. Flooded vaults make test cocks hard to reach and corrode the bolts. Testers often pump the vault before they can start.
Grizzly Backflow & Plumbing connects you with local testers in Shell Knob, MO for double check valve testing, report filing with your purveyor and repair if a check fails. Good backflow prevention depends on both checks holding, not one. Call (833) 990-5874.