Dbb Valve, SBB Valve, Flanged Dbb Valve manufacturer / supplier in China, offering Forged Steel Double Flange Dbb Valve (GAQ41F), Cast Steel Split Body Standard Port Ball Valve (116), Cast Steel Split Body Reduced Ball Valve (GARQ41F) and so on.
|Min. Order:||1 Piece|
|Transport Package:||Plywood Case|
|Payment Terms:||L/C, T/T|
|Channel:||Straight Through Type|
Work temperature: High temperature
Body material:SS,CS , FS ,A105, LCC, LCB, CF8, CF3M,etc.
Type of Connection:Flange
Driving means:Manual,worm gear.etc.
Applicable medium:Seawater,all kinds of harsh environment
Double Block and Bleed ball valve Applicable Specification
Design standard: ANSI B16.34 GB/T12237
Physical dimension: ANSI B16.10 GB/T12221
Flanges dimension: ANSIB16.10 GB/T15188.1
Test and inspection: API598 GB/T909
Double Block and Bleed ball valve structure characteristics
1. The double block and bleed valve have evolved to replace and add the process of bolting together individual valves to make the valves in one body .it saved a lot of space and material.
2. Special designs including injecting quills ,sample probes ,double block and single block, in-built check valves and seat wipers.
3. Dual isolation is necessary requirement when maintenance is taking place down stream of the first isolation valve. Cavity venting is provided by either a ball or globe OS&Y vent valve so that trapped pressure between the two isolation valves is safely vented.
4. These valves have also evolved to encompass the function of chemical injection (using a suitable quill) and sample points .In-built check valves are often integrated in these valves.
5. Fire Safe according to BS6755/API 6FA/API 607, since each sealing point is provided by a secondary fire-safe seal in graphite. Valve soft seats also are provided with secondary metal-to metal seal in case of fire.
6. Valve design can be either Trunnion or floating type ,anti blow -out stem and typically SPE seat design .Drain port is normally provide with a floating ball valve ,to be fitted with final user drain line .valve seats can be soft or metal to metal hard-faced.