Low-pressure pilot-operated type safety valve

Abstract

The invention discloses a low-pressure pilot-operated type safety valve, and relates to the technical field of valves. The low-pressure pilot-operated type safety valve comprises a guide valve and a main valve. The guide valve comprises a guide valve base, a middle valve box, a guide valve membrane, an upper valve cover, a guide valve clack and a connecting shaft. The main valve comprises a main valve body, a main valve base, a valve element rod, a main valve element, a main valve sleeve, a main valve cover, a main valve membrane and a reset spring. The area and pressure difference relation isutilized in the guide valve, the guide valve is opened rapidly, the structure sudden opening function is obvious, and opening is conducted if overpressure exists; and a full-balance structure is adopted in the main valve. The guide valve is rapid in opening and obvious in sudden opening, opening is conducted if overpressure exists, response is fast, the flow resistance coefficient character is applied in a guide valve outlet, the outlet is designed to select 10%-50%, the valve opening response is fast, and seat return is fast.

Description

technical field [0001] The invention relates to the technical field of valves, and more particularly to a low-pressure pilot safety valve. Background technique [0002] We know that the so-called safety valve is an automatic valve that plays an important role in protecting the pressure container and pipeline system. It can track the rise and fall of the medium pressure in the system and automatically open and close operations: in the pressure container and pipeline During the normal operation of the system, the opening and closing parts of the safety valve are in a normally closed state. When the pressure of the medium in the pressure-containing container and the pipeline system rises to or exceeds the set pressure value, it will automatically open to discharge the medium to the outside. Relieve the pressure and control the pressure not to exceed the set allowable value, so as to ensure that the equipment system will not have a safety accident due to excessive pressure. As ...

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Problems solved by technology

[0004] But the balance hole of the lower cavity of the cylinder of the main valve of the prior art is connected with the outlet of the main valve, so that the pressure in the lower cavity of the cylinder is the same as the pressure at the outlet of the main valve. Fully open, so that the pressure at the inlet of the main valve cannot be reduced quickly, and the pressure relief efficiency is slow, and the pilot valve structure of the prior art cannot ensure that the main valve core closes quickly after the pressure is balanced.

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