Double Block and Bleed Valves
Why use a Double Block and Bleed valve?
Double Block and Bleed valves have evolved to replace the process of bolting together individual valves to provide dual isolation.
This new assembly provides great savings in weight, space and installation times especially in instrument or instrument cage isolation. These savings can be as much as 60% in weight and studies have shown that a 70% installation time saving is also possible. However the greatest savings are to be seen in the reduction of leak paths to atmosphere, therefore reducing the risk of the potential hazards this entails.
Dual isolation is a 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.
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.
All DBB valves are manufactured to EEMUA 182 latest revision.
Double Block and Bleed valves
- Manufactured in accordance with all recognised standards including EEMUA 182 latest revision, API6D, API607,BS6755PT2, API up to 10000 and 15000 PSI
- Trunnion mounted, floating ball, and variants of gate, globe check and ball
- Special designs including injection quills, sample probes, double block and single block, in-built check valves and seat wipers
- Tested to TUV low emission standards, including cyclical testing at -46 deg C to +200 deg C
- Supplied to all major oil companies including over 2000 trunnion mounted valves to Tengiz Chevroil
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Ball needle ball double flanged with inside screw needle ventBack to top
Part of 2000 modular valves supplied to Kazakhstan in 2005Back to top
Flanged by screwed ball needle ball modular valveBack to top
Double ball isolation with ball valve vent, triple flangedBack to top
Trunnion mounted top entry ball x needle x ball design for Norwegian gas field application. Manufactured in 316 class 1500lb and 2500lbBack to top
Class 900lb gear operated trunnion mounted ball DBB with 4” bore, Inconel trim metal seated for use in the Tengiz sour gas field in KazakhstanBack to top