Advanced Pressure Testing (APT) with Acoustic Temperature Measurement

It is difficult to accurately measure leakage on large pipe volumes during pre-commissioning pressure testing. For polyethylene pipe, a period of time must elapse to avoid creep (pipe expansion due to pressure) affecting the measured pressure. Small fluctuations in temperature can also mask pressure changes resulting from leakage.

The pressure test software has built-in creep compensation algorithms, based on sound knowledge of
polyethylene behaviour.

The advanced pressure test system operated by PMI measures the temperature change of all the air in the pipe using acoustics. A loudspeaker and microphone is placed inside the pipe and a pulse echo technique is used to measure the sound speed. The speed of sound varies with temperature, which is used very effectively to determine average changes down to 0.001c. This data is then used to compensate for pressure readings.

Benefits

• Fast accurate testing
• User friendly laptop based operation
• Simple hardware installation
• Automatic test certificate generation
• Up to 75% saving on test time
• Earlier leak discrimination