Effect of temperature fluctuations during pipeline pressure testing on pressure
Thread Content
Sometimes, clients require that the pressure holding time for airtightness testing be 24 hours. There are large variations in temperature, which leads to significant pressure fluctuations. It is necessary to determine the allowable range of pressure fluctuations. Can we use the ideal gas law, PV=NRT, to calculate this? From this equation, P/T=NR/V; since N, R, and V are constant values, the P/T ratio is also constant. When the pressure reaches the value required for the pressure test and starts to remain stable, we can check what the pressure and temperature values are, and calculate the ratio of pressure to temperature (P1/T1). Let’s assume this ratio is X. If temperature fluctuations cause pressure fluctuations, then the pressure and temperature will be P2 and T2 respectively. We can then check whether P2/T2 equals X. If it does, we consider it normal. Does this approach work?
There’s no need to measure air pressure for such a long time; since you’re taking so much time, it’s necessary to make corrections using temperature, and there are calculation formulas provided in the standards.