DBB valves do not provide positive double isolation when only one side is under pressure. Therefore, the definition of a Double Isolation and Bleed (DIB) valve is to stop process from upstream getting into the downstream. It provides provable zero leakage for product segregation and transfer. DIB valves have two seating surfaces that, when in the close position, provide a seal against pressure from an upstream source and allows for the venting/bleeding of the body cavity between the two seats.
Double block and bleed expanding plug valves are designed to provide positive shut-off and verifiable zero leakage. They are ideal for Leased Automated Custody Transfer (LACT), product metering, aviation fueling, product isolation, blending, lockout/tagout (LOTO), multi-product manifolds, tank storage and other DBB applications.
To properly specify a DBB or DIB, you need to have a good understanding of your desired outcomes. Coupled with manual or automated internal body relief solutions, selecting the correct technology can be challenging. The experts at Spartan can help you select the proper valve for your application.