DBB(double block & bleed) Plug Valve Working Principle

JingGong DBB(double block & bleed) Plug Valve suitable for: aviation kerosene, light oil, natural gas, liquefied gas, pipeline gas, chemical media and other pipelines industries.

The key to the working principle of the valve with double-closing and double-breaking and relief function is the action of the two sealing slides installed on the plug.

DBB plug valve closed: when the valve is closed, first rotate the handwheel, rotate the plug and sealing slide 90 °, and then the plug moves downward, with the movement of the plug to promote the sealing slide to the inner cavity of the valve body cover until the elastic sealing ring is uniformly extruded to the upper and lower ends of the valve hole, to form a seal.

DBB plug valve opening: When the valve opens, first rotate the handwheel to lift the plug to pull the sealing slide back from the sealing surface on both sides of the valve body. When the slide is completely withdrawn from the sealing surface of the valve body, continue to turn the handwheel, so that the plug and sealing slide rotated 90 °, the valve is in the open position.

DBB plug valve sealing: the elastic sealing circle is molded in the groove of the slide, with the sealing slide to the valve inlet and outlet movement, the sealing circle is also gradually pressed into the groove, the machined surface of the slide and the inner cavity of the valve body to form a second level of gold-to-metal sealing to prevent the elastic sealing circle continues to be pressed, and has fire protection function.

DBB plug valve double shut-off and double break and release: this is a through two cut-off valves and a release valve in the middle of it to achieve the purpose of the complete isolation of the two ends of the pipeline method, close the two main valves off to open the release valve can be to improve the safety of the system. If the first valve leaks, the leaking medium can be exported by the open relief valve.

DBB plug valve double sealing method: two independent sealing slide in the valve hole on the lower end of the pressure (double shut-off), when the valve is closed, the relief valve is opened to test the sealing effect (release).

JingGong as the world's leading brand of DBB plug valves, you can ask us everything you need to know about DBB plug valves, or contact us if you have a need to purchase plug valves.

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