Movable ball valve sealing pair

Abstract

A movable ball valve sealing pair, comprising a master valve body (1) and ball-shaped spool (2) mounted in flow passage of the master valve body via a valve rod, and a sealing valve base (3) mounted on two ends of the master valve body flow passage via a end-face press-ring (4). The sealing valve base (3) is a ring-shaped sphere metal sealing valve base, a sealing pair is formed of the ring-shaped sphere of the sealing valve base (3) and sphere sealing surface of the ball-shaped spool (2), characterized in that the sealing valve base (3) is a piston type movable valve base, which fits the sphere sealing surface of the ball-shaped spool (2) in a axial liquid-force flotation mode. Characteristics of the sealing pair are that structure is rational, sealing is reliable, mechanical abrasion during valve on-off process can be avoided and valve on-off torque is decreased, ball valves with design requirements of large nominal diameter and high work pressure can be satisfied.

Description

Technical field [0001] The invention relates to a metal hard seal ball valve, in particular to a movable ball valve sealing pair suitable for a metal hard seal ball valve. Background technique [0002] At present, in the field of metal hard-seal ball valve design, the displacement of the metal hard-seal valve seat in the valve sealing pair is mostly driven by elastic elements such as springs, so that it presses the sealing surface of the valve opening and closing parts (spherical valve core) , To obtain the pre-tightening force required for valve sealing. The pre-tightening force directly affects the sealing quality of the valve and the opening and closing torque of the valve stem. In actual use, if the pre-tightening force is too large, it will cause the friction between the two sealing surfaces of the ball valve to increase Large, large opening and closing torque of the valve stem directly affects the service life of the valve; if the pre-tightening force is too small, it will ...

AI Technical Summary

Problems solved by technology

The size of the pre-tightening force directly affects the sealing quality of the valve and the opening and closing torque of the valve stem. In actual use, if the pre-tightening force is too large, the friction between the two sealing surfaces will increase when the ball valve is opened and closed. If the pretightening force is too small, it will affect the sealing effect of the valve

Since the size of the above-mentioned pre-tightening force is predetermined by the elastic coefficient of the spring and other elastic elements themselves, it is an unadjustable fixed value, which brings certain difficulties to the design and manufacture of ball valves with large nominal diameter and high working pressure.

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