Valve with bellows seal

Abstract

The invention provides a valve with bellows seal which has reasonable structure and large expansion deformation amount. The valve comprises a valve body, a valve cap arranged on the valve body, a valve clack, a valve rod, a bellows and a driving mechanism, wherein the bellows comprises a plurality of dished ring plates; the dished ring plates are provided with dished ring plate through holes for the valve rod to penetrate through; the peripheries of outer edges of the dished ring plates are outer diameters; the peripheries of inner edges of the dished ring plates are inner diameters; outer diameter end surfaces and inner diameter end surfaces of the dished ring plates are located at different planes; the inner diameters are arranged at the same side of the outer diameter end surfaces; the outer diameters and the inner diameters of each dished ring plate are sequentially staggered and are fixedly connected in a sealing way; and the centers of circles of the inner diameters of the dished ring plates are arranged at the same straight line so as to form an integral bellows. When the bellows is stretched and deformed, positions of wave crests and wave troughs of the bellows basically do not become deformed, therefore, the deformation amount of the bellows is higher than that of the traditional bellows, the structure is more compact and reasonable, and the sealing effect is more obvious.

Description

technical field [0001] The invention relates to a valve, especially a valve with a bellows seal. Background technique [0002] For some valves used to transmit toxic and dangerous media, it is usually required that the valve stem has excellent sealing performance to prevent the leakage of toxic and dangerous substances. Packing seals, but the packing seals are usually prone to aging and leakage after a period of use, which brings great danger to users. Such as figure 1 As shown, in order to make the sealing effect at the valve stem more reliable, bellows are usually used as the seal to seal the valve stem at present, which is the so-called bellows valve. This bellows valve is obtained in many occasions with strict sealing requirements. However, the stem stroke of many bellows valves is very large, especially bellows gate valves and large-diameter bellows stop valves. The crests and troughs on the bellows are arc-shaped, and the wall thickness of the single bellows produce...

AI Technical Summary

Problems solved by technology

However, because the bellows needs to withstand huge medium pressure, and the wall thickness of the bellows is small, the joint of the bellows usually becomes the weakest part of the bellows, and the defect of the welding part usually leads to the sealing failure of the bellows

[0003] In addition, because the bellows is very thin and the valve stem is very thick, the thickness of the two is very different. It is usually easy to weld the bellows through during the welding process of the bellows and the valve stem. The weak part of the pipe valve, and the defect of the welding part will cause the sealing failure of the bellows

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