The double offset butterfly valve is gradually improved by the ordinary butterfly valve to adapt to different working conditions. The earliest butterfly valve structure is mainly the center door panel structure, similar to the adjustment butterfly valve, that is, the axis of the valve stem and the butterfly plate coincides with the center of the valve body pipe.
Butterfly valves are used in a wide range of applications and are suitable for flow regulation. Because the butterfly valve has a large pressure loss in the pipeline, it is about three times that of the gate valve.
The valve stem axis simultaneously deviates from the disc center and the body center, and the valve seat turns the axis and the valve body channel axis has certain Angle, is called the Triple offset butterfly valve
The axial center of the valve stem is simultaneously deviated from the center of the disc and the center of the body, and the rotation axis of the valve seat has a certain angle with the axis of the valve body passage, which is called triple offset butterfly valve.
The double offset butterfly valve is characterized in that the shaft center of the valve stem is offset from both the center of the disc and the center of the body. The double offset effect allows the disc to be quickly disengaged from the valve seat after the valve is opened, which greatly eliminates unnecessary over-squeezing and scraping of the disc and the valve seat, reduces the opening resistance, reduces wear and improves the seat life.
The two eccentricities of the double offset butterfly valve refer to the eccentricity of the rotating center line of the disc and the eccentricity of the sealing line and the eccentricity of the center line of rotation of the disc and the center line of the channel.
Further improved molding on the basis of the single offset butterfly valve is currently the most widely used double offset butterfly valve. The structural feature is that the stem axis is offset from the center of the disc and from the center of the body.
The offset butterfly valve is divided into single offset butterfly valve, double offset butterfly valve, and triple offset butterfly valve. A butterfly valve whose valve stem axis is at the same time deviated from the center of the disc and the center of the body, and whose sealing pair is a slanting vertebra is called an offset butterfly valve.
The superior performance of butterfly valve is closely related to their constant eccentricity, evolution and development. In order to meet various working conditions, the butterfly valve has experienced the evolution from concentric to single eccentricity, double eccentricity and triple eccentricity.
A butterfly valve is a valve in which a closing part is a disc that rotates around the valve shaft to open and close, and is mainly used for cutting and throttling on the pipeline.