Double Block & Bleed
Double Block and Bleed is available on any size and pressure class. A simple change to the core, adding a seal on both ends, will isolate the body cavity. The body can then be vented and checked for pressure buildup verifying the double block. In the event that a valve has trapped body pressure the self-relieving feature will equalize with the upstream side of the valve. An important differentiation between the Chromatic DBB and a standard ball valve is how it relieves this pressure. The standard double block and bleed valve is designed with self-relieving seats to the downstream side. If a standard ball valve has a leaking upstream seat then upstream pressure can continually pass downstream. The HCV maintains its Reliable Mechanical Wedge Seal on the downstream side providing a more effective seat.