Butterfly valve with adjustable shaft seal structure

Abstract

The invention discloses a butterfly valve with an adjustable shaft seal structure. The butterfly valve with the adjustable shaft seal structure comprises a valve rod, a valve body, a transition flange and an executor, wherein the adjustable shaft seal structure is arranged between the upper portion of the valve body and the lower portion of the transition flange and comprises sealing packing, a packing gland, a pressing plate, a bolt and a nut. The sealing packing is arranged in an annular groove formed by the upper end surface of an upper lining sleeve, the valve rod and a hole in the upper end of the valve body, the pressing plate and the packing gland are arranged on the valve rod in a sleeved mode from top to bottom, the bolt penetrates through through holes in the two ends of the pressing plate and fastens the pressing plate to the upper end of the valve body through the nut, the lower end of the packing gland is pressed on the upper end surface of the sealing packing, the upper end of the packing gland is provided with a protruding spherical surface which is matched with a concave spherical surface groove in the center of the lower end surface of the pressing plate, and the sealing packing is a V-shaped fluoroplastic packing ring. The shaft seal adjustable butterfly valve can adjust the matching between the sealing packing and the valve rod to a tight state and guarantee sealing performance, thereby guaranteeing the sealing effect for a long time.

Description

technical field [0001] The invention relates to a butterfly valve. Background technique [0002] For a butterfly valve system consisting of a butterfly valve, a transition flange and an actuator, a shaft seal structure is generally provided between the upper part of the valve body and the lower part of the transition flange. The shaft seal structure of the butterfly valve stem in the prior art is a radial shaft seal structure between the upper and lower bushes and the valve stem of the butterfly valve. Embedded O-shaped sealing ring is formed by sealing with the valve stem. This structure can effectively prevent the liquid passing through the butterfly valve from overflowing, but once the O-ring is worn out, its sealing performance will decrease, and the liquid passing through the butterfly valve will overflow from the gap between the sealing ring and the valve stem. The lower end of the valve stem has an axial shaft seal structure formed by the end cover, which ensures th...

AI Technical Summary

Problems solved by technology

In order to ensure the tightness of the upper end of the butterfly valve stem, it is necessary to disassemble the butterfly valve, remove the upper bushing, replace the seal, and then reassemble, which is time-consuming and troublesome.

Images