The Double Block & Bleed Ball Valve

Double Block and Bleed Ball Valve (DBB, Flanged, Twin Gear Operators)

This double block and bleed (DBB) valve integrates two trunnion-mounted ball valves in series with a central bleed valve within a single compact body, replacing the traditional installation of two separate isolation valves plus a bypass spool. It provides verified double isolation with a cavity bleed connection, allowing operators to confirm zero downstream pressure before maintenance. The all-welded or bolted one-piece body reduces weight, footprint, and potential leak points compared to fabricated manifold assemblies.

Each ball valve is operated independently through its own worm-gear operator and handwheel, enabling staged isolation procedures. The central bleed valve vents the cavity between the two seals and can be connected to a flare or drain system. Additional connections include body vent, drain, and grease injection fittings. The valve is supplied with a support skid for stable mounting. Flanged ends are drilled to ASME B16.5, with RTJ or raised-face options.

Typical applications include custody transfer metering stations, gas regulation and metering skids, compressor stations, scraper stations, and tank farm isolation in oil and gas transmission. Designed to API 6D and ASME B16.34, tested per API 598. Body materials include A105, WCB, LF2, LCC, and stainless steel. Fire-safe (API 607) and NACE MR0175 sour-service options are available.

Product packaging

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