Double Block and Bleed Plug Valve
Structural Features
The double block and bleed plug valves have commonly been used for primary and secondary tight shut off, in an attempt to provide and ensure system integrity. Previously, the system integrity needed two individual isolation valves, a spool piece and a bleed valve that not only caused extensive costs and weight but also were increasing the risk of emissions due to multiple flanged faces.
These DBB plug valves have a single body with dual Plug valves with a bleed valve installed between the two main line valves and are available bi-directional with metal seat or rubber seat, both in ANSI Class VI.
They replace existing traditional techniques employed by pipeline engineers to generate a double block and bleed configuration in the pipeline.
- Actuators, gear boxes and extended handles can be offered for these valves
- Cryogenic and high-temperature applications are available
- Soft or metal seated
Structural information . | BB-BG-OS&Y |
Diving manner | Handwheel, bevel gear wrench |
Design standard | AP1599, API6D |
Face to face | ASME B16.10 |
Flange end | ASME B16.5 |
Test&inspection | API598,API6D |
Note: the size of serial valve connecting flange can be designed according to customers’ requirement.
No. | Part name | Material |
1 . | Body . | ASTM A216-WCB, ASTM A217-WC1, WC6, WC9, C5, ASTM A351-CF8, CF8M, CF3, CF3M |
2 | Plug | ASTM A216 WCB+N, ASTM A351-CF8, CF8M, CF3, CF3M |
3 | Gasket | Flexible graphite+stainless steel, PTFE |
4 | Cover | ASTM A216-WCB, ASTM A217-WC1, WC6, WC9, C5, ASTM A351-CF8, CF8M, CF3, CF3M |
5 | Bolt | ASTM A193-B7, A320-B8A193-B8M |
6 | Nut | ASTM A194-2H, A194-8, A194-8M |
7 | Packing | Flexible graphite, PTFE |
8 | Gland | ASTM A216-WCB, ASTM A217-WC1, WC6, WC9, C5, ASTM A315-CF8, CF8M, CF3, CF3M |
9 | Wrench | ASTM A216-WCB, ASTM A351-CF8, CF8M, CF3, CF3M |
10 | Yoke nut | Copper alloy ZQA19-4 |
11 | Handwheel | ASTM A536 Gr.60-40-18, ASTM A216-WCB |

Headquarters and Factory
Anfeng Industrial Park – Dong’ou Industrial Zone, Oubei, Wenzhou
International Sales Office
Via A. Moro, 61 San Donato M.se Milan – Italy
☎ Phone: +39 02 87 166 867
✉ E-mail: export@zhedong-valve.com
✉ E-mail: sales@plugvalvefactory.com