Double Block & Bleed Valve A VALVE IS A DEVICE THAT REGULATES, DIRECTS OR CONTROLS THE FLOW OF A FLUID BY OPENING, CLOSING, OR PARTIALLY OBSTRUCTING VARIOUS PASSAGEWAYS. Valves are technically valves fittings, but are usually discussed as a separate category. Double Block & Bleed Valve Blow-out proof design with internally loaded stem further Floating Ball design providing seat wear compensation and high integrity. Catalog Spec. Reduced potential leak paths with primary & secondary isolation in one valve. Compact ball/OS&Y/needle valve assembly in one DBB. Flange construction as per the requirements of ASME B16.5 NPT threaded connection to ANSI/ASME B1.20.1 Pressure rations as per ASME B16.34 Class 150 thru 2500. Wetted components of Sour gas service valve are selected as per the requirements of NACE MR0175/ISO 15156 Fire tested as per BS 6755 part 2/API607 Anti-Static Device is set between the stem and ball.