Double block bleed valve
Double block bleed valve (special cock valve, collectively referred to as DBB Valve in the world) is a valve with dual shut-off and relief functions. The wedge-shaped rail design is used to keep the valve between the seal and the valve body during the opening and closing process. A certain clearance avoids the problem of easy wear and abrasion of the sealing surface that is common in valves. Compared with ordinary valves, the double block bleed valve has the advantages of small opening and closing torque, good sealing effect and longer life.
The double block bleed valve (special plug valve) mainly has the following characteristics:
(1) Double-sealing and zero-leakage Double-sealing structure is adopted, upstream and downstream are sealed at the same time, and each sealing surface has two types of soft and hard seals. The soft seal ensures zero leakage of the valve, and the hard seal protects the soft seal. With fire protection function.
(2) No wear and long life. The valve uses the oblique wedge principle. During the opening and closing process, there is no wear between the seals, which fundamentally guarantees the service life of the valve. Our company commissioned the Hefei General Machinery Research Institute to carry out the static pressure life test, and the number of opening and closing times for the test was 28,000.
(3) On pipeline repair and replacement of parts is possible. When the main seal of the valve is damaged, the valve can be repaired and replaced without removing the valve from the pipeline. The entire replacement operation is simple and convenient without special tools and equipment assistance.
(4) Leak detection and cavity relief function When the valve is closed, the internal leakage detection of the valve and the relief and pressure reduction of the valve cavity can be performed by opening the pressure relief valve.
(5) Sewage discharge function The bottom of the valve is designed with a sewage outlet, which can discharge the sediment in the medium through the sewage outlet.
Main parameters of double block bleed valve (special plug valve):
1. Nominal diameter: DN25～600(1″～24″)
2. Nominal pressure: PN1.6, 2.5, 4.0, 6.4, 10.0MPa
PN150, 300, 600Lb
3. Leakage amount: zero
4. Operating temperature: -46℃～250℃
5. Material quality: carbon steel WCB, WCC, LCB, LCC; stainless steel CF8, CF8M, CF3, CF3M
Application range of double block bleed valve (special cock valve): oil refining and storage and transportation of oil products (crude oil, light oil, kerosene, aviation kerosene, etc.); storage and transportation of various chemicals (various acids and alkalis and chemical media); municipal, Gas storage and transportation (city gas, natural gas, pipeline gas, etc.); power system (steam, fuel, etc.).
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