Double-scraper diaphragm butterfly valve

Abstract

The invention discloses a double-scraper diaphragm butterfly valve. The double-scraper diaphragm butterfly valve is characterized in that a valve body, a support and an execution mechanism are included, and the support and the execution mechanism are sequentially connected with the valve body; a butterfly plate is arranged in the valve body; a tetragonal-prism-shaped groove ring lug and a cylindrical groove ring lug which are parallel to the plane of the butterfly plate are arranged above and below the rear end of the butterfly plate; a tetragonal-prism-shaped upper valve rod is arranged in the tetragonal-prism-shaped groove ring lug; a cylindrical lower valve rod is arranged in the cylindrical groove ring lug; the butterfly plate is further connected with a sealing structure, and the sealing structure comprises a valve seat pressing plate, a valve seat, a diaphragm ring, a pressing plate ring, a butterfly plate sealing pad, a front pressure cavity and a rear pressure cavity; and a diaphragm front end thrust groove, front through-flow holes and pressing plate bolt holes are formed in the pressing plate ring. The elastic diaphragm pressure self-sealing structure is adopted, the diaphragm front end thrust groove and a diaphragm rear end thrust face achieve the function of scrapers, and special connection of the upper valve rod and the lower valve rod and locking prevention are achieved; low twisting force and the small structure are achieved, and compressive resistance is high; and the butterfly valve has the beneficial effects of being reliable in performance and long in service life.

Description

technical field [0001] The invention relates to the technical field of pipeline accessories, in particular to a double-scraper diaphragm butterfly valve. Background technique [0002] Existing butterfly valves, such as centerline butterfly valves, are composed of a metal valve body and then embedded with a rubber sleeve. The middle butterfly plate is rotated and squeezed to seal. The extrusion contact sealing area between the butterfly plate and the rubber sleeve is relatively narrow, and there is no pressure self-sealing. Therefore, the sealing pressure is low, and the seal is easily damaged by frequent extrusion. Because the integral rubber sleeve is used, the material of the rubber sleeve is too high, the cost is too high, and the rubber material used is easy to age, so the general sealing pressure of the centerline butterfly valve Low, short service life, such as eccentric butterfly valve, the eccentric sealing structure adopted, using the track law of the eccentric butt...

AI Technical Summary

Problems solved by technology

[0002] Existing butterfly valves, such as centerline butterfly valves, are composed of a metal valve body and then embedded with a rubber sleeve. The middle butterfly plate is rotated and squeezed to seal. The extrusion contact sealing area between the butterfly plate and the rubber sleeve is relatively narrow, and there is no pressure self-sealing. Therefore, the sealing pressure is low, and the seal is easily damaged by frequent extrusion. Because the integral rubber sleeve is used, the material of the rubber sleeve is too high, the cost is too high, and the rubber material used is easy to age, so the general sealing pressure of the centerline butterfly valve Low, short service life, such as eccentric butterfly valve, the eccentric sealing structure adopted, using the track law of the eccentric butterfly plate in the rotation stroke, set the corresponding position of the valve seat to closely seal, because the valve seat and the butterfly plate are fixed The type of close-fitting seal does not have too much elastic compensation or other means of thrust, and the contact area of ​​the sealing surface is relatively small, so the sealing pressure will not be too high, and a little impurity in the pipeline medium will be rubbed on the sealing surface , it is easy to cause leakage, and the more the leakage is, the larger the use state is, and the processing difficulty is also great

In the existing butterfly valve, the square cylindrical upper valve stem and the butterfly plate are connected in a cylindrical shape with pins, and the cylindrical lower valve stem and the butterfly plate are connected with pins. Over time, the pins are aged and disconnected, which will cause the valve stem and the butterfly plate to be disconnected due to aging. Board out of control

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