Pilot-operated safety valve with modulation characteristic

Abstract

The invention provides a pilot-operated safety valve with modulation characteristic, which comprises a main valve and a modulation type guide valve, wherein a valve seat of the modulation type guide valve is fixed in the lower part of a cavity of a guide valve body; a guide valve piston is arranged above the cavity in the guide valve body and the valve seat of the guide valve; the middle upper part of a guide valve shaft is installed in the guide valve piston, and the lower part thereof is arranged in the valve seat of the guide valve; the connecting part between the upper part of the guide valve shaft and the guide valve piston is provided with an inlet sealing ring; and the connecting part between the lower part of the guide valve shaft and the valve seat of the guide valve is provided with an outlet sealing ring. The pilot-operated safety valve can be used for effectively controlling the pressure of an air chamber of the main valve, leads the pressure of the air chamber to be slowly reduced along with the augment of overpressure value, and ensures the opening height of the main valve to be gradually changed along with the overpressure value, thus guaranteeing the circulation area to be changed along with the demand of release quantity; and the discharge capacity can be adjusted according to the actual demand of the system for overpressure protection.

Description

technical field [0001] The invention relates to a pilot-operated safety valve used for overpressure protection of a pressure system, in particular to a pilot-operated safety valve with modulation characteristics. Background technique [0002] The pilot-operated safety valve is a non-direct acting safety valve, which consists of a main valve and a pilot valve, and relies on the medium discharged by the pilot valve to drive or control the opening of the main valve. The common pilot-operated safety valves on the market are sudden-opening pilot-operated safety valves, the main valve of which can be fully opened under a small overpressure condition, and the action is rapid. Due to the rapid opening and closing action of the pop-up pilot valve, if it is applied to a liquid medium, it is very easy to cause water hammer, so this type of product can only be used in gas and steam conditions; When the valve is small, it can be fully opened, so the actual amount of medium discharged wi...

AI Technical Summary

Problems solved by technology

Due to the rapid opening and closing action of the pop-up pilot valve, if it is applied to a liquid medium, it is very easy to cause water hammer, so this type of product can only be used in gas and steam conditions; When the pressure is small, full opening can be achieved, so the actual amount of medium discharged will be greater than the overpressure relief required by the system

[0003] Due to the problems that the pop-open pilot safety valve cannot be used for incompressible media and the discharge capacity cannot be adjusted, the demand for modulating pilot valves is very urgent in the market.

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