On-line verification system and method of pilot-operated safety valve

Abstract

The invention discloses an on-line verification system and method of a pilot-operated safety valve. The on-line verification system and method is used for performing on-line verification on setting pressure of a guide valve and a main valve of the pilot-operated safety valve on a flammable, combustible, low-temperature and low-pressure storage tank. The on-line verification system comprises a fourth control valve, a balancing cylinder, a pressure measurement pipe, a first control valve, a liquid supplement device and a test pressure recorder, wherein the four control valve is arranged on a pressure guide pipe between the guide valve and the main valve of the pilot-operated safety valve, the balancing cylinder, the pressure measurement pipe, the first control valve and the liquid supplementdevice are sequentially connected by a guide pipe, the pressure measurement pipe is used for loading a liquid to compress a gas in the balancing cylinder so as to raise working pressure of the pilot-operated safety valve until the guide valve is opened, the liquid supplement device is used for storing the liquid, the test pressure recorder is arranged on the pressure measurement pipe and is usedfor recording height change of a liquid level in the pressure measurement pipe in real time, the fourth control valve is connected with the balancing cylinder by the guide pipe and is used for controlling conduction of the guide valve and the balancing cylinder, and the pressure measurement pipe and the balancing cylinder form a U-shaped structure. With the on-line verification system of the pilot-operated safety valve, disclosed by the invention, verification can be performed in a site, and off-line verification is performed without disassembling the pilot-operated safety valve.

Description

technical field [0001] The invention relates to the technical field of safety valve calibration, in particular to an on-line calibration system and method for a pilot-operated safety valve. Background technique [0002] At present, my country's energy consumption structure is changing from coal fossil-based fuel to clean energy-based natural gas, and a large number of natural gas storage stations have been built in Shenzhen. In order to improve the efficiency of natural gas (methane) in the process of transportation and storage, the international mainstream technology is to cool down the natural gas and store it at low temperature (-190°C). During storage, tanks storing cryogenic natural gas may absorb heat due to insulation efficiency, causing an unexpected increase in tank pressure. In order to ensure safety, a safety valve is required to be installed on the roof (gas phase space) of the cryogenic LNG storage tank. The type of safety valve is generally a pilot-operated s...

AI Technical Summary

Problems solved by technology

[0011] The technical problem to be solved by the present invention is that, in view of the large size of the pilot-operated safety valve in the prior art, it takes time and effort to dismantle the off-line calibration, the working pressure of the pilot-operated safety valve is low, the traditional pressure gauge cannot measure, and the working environment of the pilot-operated safety valve is It is flammable and explosive, the pressure sensor that needs electricity cannot be used, and liquefied natural gas is a flammable and explosive medium, and the calibration medium cannot use a gas medium with oxidizing chemical properties. A pilot-operated safety valve online calibration system is provided. and method

Images