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Double close double block valve

Double close double block valve


  Working principle

  The double off, double break and relief function valve is characterized by the vertical movement of the seal sliding surface with respect to the valve body sealing surface, and the elastic sealing ring is used to transfer the wear to the & quot; wedge & quot; design on the intermediate surface (cock and sliding vane guide rail), which completely eliminates the common problems of common valves: wear and scratch of seals. In the process of rotation, there is always a certain clearance between the seal and the sealing surface of the valve body. The seal can rotate freely, there is no friction between the sealing surfaces, and the seal will not be worn.



  1. The seal sliding plate and cock adopt the unique oblique wedge dovetail guide structure. Through the unique transmission structure, the sliding vane sealing surface has no contact with the valve body sealing surface in the process of opening and closing. Therefore, the sealing surface has no friction and wear. The service life of the valve only depends on the aging speed of rubber, which greatly extends the service life of the valve, and the switching torque of the valve is small.

  2. The valve adopts double sealing structure, the upstream and downstream are sealed at the same time, and each sealing surface has soft and hard seals. The soft seal ensures zero leakage of the valve, and the hard seal has protective effect on the soft seal, and the hard seal has fire prevention function.

  3. The double sealing structure is adopted in the flange seal and packing seal to ensure that the medium will not leak out.

  4. All surfaces in contact with the medium are plated with rust proof and wear-resistant metal chromium or nickel.

  5. The valve has the function of on-line maintenance. The sealing sliding plate is connected with the cock by dovetail groove. If the soft seal damage device on the sealing sliding plate needs to be replaced, it is not necessary to remove the whole valve from the pipeline, just remove the valve bottom cover, pull out the old slide, replace with a new slide, and install the bottom cover.

  6. There are two kinds of valve flow path: full bore and Venturi reducing. Full bore valve is suitable for pipeline requiring ball cleaning, while venturi reducing valve is suitable for pipeline without ball cleaning.

  7. A pressure relief device is installed on the valve to prevent abnormal pressure rise in the valve chamber after the valve is closed, and the sealing effect of the valve can be inspected.

  8. The valve has an on-off indicator. The indicator is synchronized with the switch position of the valve, which can accurately display the opening and closing status of the valve.

  Design standards: API 6D, GB / t12220, GB / t12224, GB / t12229, GB / t12231

  Structural length: ANSI B16.10, GB / t12221

  Connection standards: ANSI B16.5, JB / T 79.1, JB / t79.2, GB / T 9113, Hg / t20592

  Pressure test: API598, JB / t9092, GB / t13927

  Body material: WCB LCB

  Nominal diameter: full bore DN80 ~ DN600 (NPS 3 ″ - NPs 24 ″) venturi reduced diameter DN80 ~ DN700 (3 "~ 28")

  Pressure range: 1.6Mpa ~ 6.4Mpa (150l300l)

  Working temperature: - 46 ℃~ + 200 ℃

  Double off, double break and relief function (forced sealing valve) valve is suitable for: aviation kerosene, crude oil, product oil, natural gas, liquefied petroleum gas, pipeline gas, chemical industry, metering system and other media on the pipeline, as the best and ideal device to cut off the medium.


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