Cascaded type zero-leakage valve interior assembly

Abstract

Disclosed is a cascaded type zero-leakage valve interior assembly. The lower end of a guide sleeve is connected with an upper sleeve in a butting mode. The external diameter of a large valve element is matched with the internal diameter of the upper sleeve. A circumferential groove is formed in the inner side of the lower end of the guide sleeve, and a sealing ring which makes contact with the upper end of the upper sleeve and the large valve element is arranged in the circumferential groove. A valve element cavity is formed below the top wall of the large valve element, a disk spring is arranged in the valve element cavity, and the lower end of the disk spring makes contact with a small valve element. The small valve element is divided by a sealing surface into an upper portion and a lower portion, the upper portion of the small valve element is located in the valve element cavity, a circumferential groove is formed in the side wall of the upper portion of the small valve element, and a sealing ring is arranged in the circumferential groove. The internal diameter of an opening formed in the top end of a lower sleeve is smaller than that of the upper sleeve, a circumferential groove is downwards formed in the top end of the lower sleeve, a soft valve seat is arranged in the groove, the outer ring of the soft valve seat is kept making contact with the lower end of the upper sleeve, and the width of the inner ring of the soft valve seat is larger than the wall thickness of the lower end of the large valve element. According to the cascaded type zero-leakage valve interior assembly, a dual-sealing structure with a protecting function is adopted, a soft seal is closed after a hard sealing surface makes contact with water, and therefore internal leakage of a valve can be effectively avoided, and the scour damage to a soft sealing surface in a short period can be avoided.

Description

[0001] Technical field: [0002] The invention relates to the technical field of regulating valves, in particular to a cascaded zero-leakage internal valve assembly. [0003] Background technique: [0004] At present, the recirculation regulating valve of the feed water pump is used at a pressure difference of 25MPa or even 30MPa. The hard sealing surface is prone to internal leakage, but the soft sealing is not resistant to erosion; in addition, high-pressure saturated water is most likely to cause flashing and cavitation damage. , so the current feed water pump recirculation control valve life is very short. [0005] Invention content: [0006] In view of this, it is necessary to design a cascaded zero-leakage internal valve assembly that can overcome the above problems. [0007] A cascaded zero-leakage valve internal assembly, including: a large valve core, a small valve core, a disc spring, a guide sleeve, an upper sleeve, a lower sleeve, a first spring energy storage sea...

AI Technical Summary

Problems solved by technology

[0004] At present, the recirculation regulating valve of the feed water pump is used at a pressure difference of 25MPa or even 30MPa. The hard sealing surface is prone to internal leakage, but the soft sealing is not resistant to erosion; in addition, high-pressure saturated water is most likely to cause flashing and cavitation damage. , so the service life of the current feedwater pump recirculation control valve is very short

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