What is the sealing principle of the single eccentric sealing butterfly valve?

The sealing principle of single eccentric sealing butterfly valve:

1. Structural features: The center of rotation of the valve disc (the center of the valve shaft) is located on the centerline of the valve body, and forms an α dimension offset with the sealing section of the valve disc.

2. Sealing principle: Since the center of rotation of the valve disc (the center of the valve shaft) and the sealing section of the valve disc are eccentrically set according to α the valve disc and the sealing surface on the valve seat form a complete circle, so it is easier to guarantee the surface roughness value of the sealing surface for the valve disc and the valve seat during processing.

It can be seen from the A-A sectional view in the figure below that when the single eccentric sealing butterfly valve is in a fully open position, disc sealing surface will be completely separated from the body sealing surface, forming a gap x between the valve disc sealing surface and the body sealing surface. When the valve disc of the butterfly valve is opened from 0^O to 90^O, the sealing surface of the valve disc will gradually separate from the sealing surface of the body seat. In the usual design, when the valve disc rotates from 0^O to 20^O ~ 25^O, the sealing surface of the valve disc can be completely separated from the sealing surface of the body seat, so that during the opening and closing process of the butterfly valve, the relative mechanical wear and squeeze between them is greatly reduced, and the sealing performance of the butterfly valve is improved.

When the butterfly valve is closed, through the rotation of the valve disc, the outer sealing surface of the valve disc gradually approaches and squeezes the PTFE body seat, so that the PTFE body seat is elastically deformed to form an elastic force as the sealing specific pressure to ensure butterfly valve seal.

More details of butterfly valves, please go to https://www.mingpinmetals.com/Butterfly-Valve-pl3507724.html