Double Block and Bleed Valves
TRI-BLOCK (DOUBLE BLOCK AND BLEED) - Zwick Armaturen GmbH

SERIE TRI-BLOCK
DOUBLE BLOCK AND BLEED
The Double Block and Bleed design features every technical advantage which the series TRI-CON has plus there is a true double block and bleed feature which delivers zero leakage. By using this design, the former two valve system with a spool piece becomes obsolete. This fact is not only important for installation since you have to install only one valve body in the pipeline, but also only one actuator or gearbox is required.
With ZWICK’s unique design of the linkage between the two shafts, the user is able to actuate both shafts with only one actuator and reach zero leakage with the two available sealing surfaces.


ECONTROL Block and Bleed Valves - Single and Double

ECONTROL Double Block and Bleed main applications:
• Instrument DBB for chemical injection and process sampling
• Instrument DBB for process connections (insulation of pressure indications or gauges)
• In-line DBB for process isolation located in the primary process line
The ECONTROL BB-100 and DBB-100 single and double block and bleed valves (BB and DBB) are isolation devices that feature two in-line isolation valves and a bleed point, used to drain or vent trapped fluid between the two line closure elements, in order to safely isolate the downstream piping. The expanding activity in the oil and gas offshore sector and the energy industry leads to additional factors that have to be taken into consideration when designing piping systems. Space in these locations is always an issue and the design of piping systems and their associated components must therefore be more compact. There are structural constraints that are also very important, such as keeping the structure as light as possible, and there are obvious benefits from making components smaller and lighter. Construction site job is also very expensive and any reduction in installation manpower is also beneficial.
Double Block and Bleed main applications:
• Instrument DBB for chemical injection and process sampling
• Instrument DBB for process connections (insulation of pressure indications or gauges)
• In-line DBB for process isolation located in the primary process line
The BB and DBB valves are mainly used in offshore oil and gas production and terminals, refining as well as in LNG carriers because those are an ideal solution that save space and weight, installation costs and increase safety (minimize potential leak source and maximize pipe structural integrity). Process isolation philosophy has become more complex as safety issues have to be addressed and the requirement for double block and bleed isolation has become more commonly used. Double Block and Bleed isolation requires two in-line isolation valves and a bleed valve, used to drain or vent trapped fluid between the two closure elements. Multiple ESDV+MOV as well as ESDV+XV configurations are available.
Specification
Manufactured sizes | NPS 1/4″ thru NPS 88″. Higher or special sizes may be developed upon request, please enquiry |
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Pressure ratings | ANSI 150#, ANSI 300#, ANSI 600#. ANSI 900#, ANSI 1500#, ANSI 2500#, ANSI 4500#. Please enquiry for higher or lower ratings |
Valve connections | ASME B16.5 (FF, RF, RTJ, Threaded), ASME B16.47 Series A or B, MSS SP-44, ASME B16.25 (BW, SW, WE). Please enquiry for special connections |
Standardization | API 6D / ISO 14313, ASME B16.34, BS 5351, API 608, BS EN ISO 17292, API 6FA, BS 6755 Part 2, ASME B16.10, API 598, GOST, JIS, NACE 01-MR-0175. Please enquiry for other standards |
Materials
Body | ASTM A216, A105, A350, A182, A351, A352, A890, A995, C95300, C95800, MONEL, INCONEL. Please enquiry for different material configurations |
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Trim | ASTM A216, A105, A350, A182, A351, A352, A890, A995, C95300, C95800, MONEL, INCONEL. Please enquiry for different material configurations |
Seat(s) | PTFE, NYLON, PEEK, NBR, KELF, ENP (Electroless nickel plating), HC (Hard chrome), TC (Tungsted carbide). Please enquiry for different material configurations |
Sealing | BUNA-N, EPDM, VITON, Flexible graphite, FKM, HNBR, Nitrile, Neoprene. Please enquiry for different material configurations |
Product Range

20" ANSI 300# Double Block and Bleed Valve during packing stage

1" ANSI 150# Block and Bleed Valve during preparation for testing
