The judgment of internal leakage of oil and gas pipeline valves are analyzed (2)

From previous news we know what causes the internal leakage of valve. With the development of society and the progress of science and technology, the safety reliability and service life of valves in oil and gas pipelines are increasingly required. If the internal leakage of pipeline valve is not found in time, it may bring serious safety risks to the oil and gas industry, and then cause huge economic losses. So ,how to judge the valve internal leakage?

This paper mainly to judge the valve internal leakage.

(I) Formula method

When the valve is closed and there is no pressure in the back line or pressure vessel, it is possible to determine whether the valve has internal leakage by the change of pressure in the line or vessel.

(2) The blowdown method

When it is not possible to determine whether the valve has internal leakage through the back line or pressure vessel, we can use the blowout method. First we need the adjustment of valve to close position, especially the ball valve with a balance ball must be placed in a seated position, then slowly open the drain valve of the valve for drain work, if the oil and gas in the valve cavity can completely do, means that the valve without leakage, if not, then in existence of valve leakage.

(3) Flowmeter leak detection method

Flowmeter leakage measurement method is a very simple method to determine whether the oil and gas pipeline valve internal leakage. After a transfer joint, need to be ready in advance on the drain plug and drain valve valve assembly on a range of about 0.2 litres/minute float precision meter direct reading type or surface type gas flowmeter, finally from the flowmeter can directly read out the corresponding leakage, directly determine the existence of oil and gas pipeline valve leakage.

(4) Valve internal leak test tool method

We use the pipe fitting and the precision pressure gauge to make the valve internal leakage detection tool. If the pressure in the valve chamber does not rise after discharge, we can conclude that the pipeline valve has no internal leakage, otherwise the valve has internal leakage.

In recent years, the internal leakage of oil and gas pipeline valve occurs frequently, seriously affecting the safety production operation of the whole oil and gas pipeline work. In the actual pipeline transportation work, it is necessary to avoid the occurrence of valve leakage in oil and gas pipeline as far as possible. Constantly strengthen the valve operation, maintenance, maintenance management, actively looking for new technology of pipeline equipment maintenance, to avoid the occurrence of oil and gas pipeline valve leakage phenomenon.