The double block and bleed ball valve

Product Description

The double block and bleed ball valve is make up by two ball valve and one needle valve or two ball valve and a globe valve. it is also called DBB valve. Welcome you visit our web 3w.gvballvalve.com to get more information. 

Brand name:GOOLE VALVE
Model number:DBB*1F 
Nominal Diameter:DN**-DN***0
Pressure:**0LB****0LB
Work temperature: High  temperature
Body material:SS，CS , FS ,A**5, LCC, LCB, CF8, CF3M,etc.
Type of Connection:Flange
Driving means:Manual,worm gear.etc.
Flow direction:bidirectional
Applicable medium:Seawater，all kinds of harsh environment

Applicable Specification
Design standard: ANSI B*6.*4     GB/T****7
Physical dimension: ANSI B*6.*0    GB/T****1
Flanges dimension: ANSIB*6.*0     GB/T****8.1
Test and inspection: API**8        GB/T***2

DBB 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 BS***5/API 6FA/API **7, 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.

Welcome you visit our web: gvballvalve.com to get more information , if you have any doubt you can feel free to contact us ,we will try our best to provide you with quality service.