What are the reasons for using water pressure for PE pipe pressure test

Update:23-09-2020
Summary:

In the compression test of pe pipes, the compression te […]

In the compression test of pe pipes, the compression test is generally selected because of the variability of gaseous substances.

 

The gas has the following characteristics, which is unfavorable for the compression test of plastic pipes:

 

(1) The volume is not restricted, and the fluidity rate is fast. The gas can diffuse, and its volume is not limited. After the gas enters the PE pipe, it will fill up the entire space, which is very easy to shrink and stretch, and the gas flow rate is too fast, which will cause the inner wall of the PE pipe to suffer a momentary impact from the gas and cause damage.

 

 

(2) The volume is greatly affected by temperature. The heat capacity of the gas is small, and its volume is greatly harmed by temperature, especially when the surrounding working temperature rises, it will cause expansion, resulting in a momentary increase in working pressure in the pipeline, causing engineering blasting, which poses a safety risk.

 

(3) The pipeline leakage cannot be assessed. Because the gas cannot be seen or touched, if the gas pressure test is selected, it is not easy to detect the presence of electricity in the PE pipeline.

 

Part of the reason why the water pressure test is selected is that the physical properties of water substances are more stable relative to gas substances. The airtightness and compressive strength tests of PE pipes must use water as the substance, and the pressure test method should be used for testing. It is strictly forbidden to carry out pressure test with gas as a substance.

 

Due to the stability of the physical properties of the water substance, the working pressure on the inner wall of the pipe is relatively even. Make the actual effect of the pipe compressive strength test (ie pressure bearing capacity) more accurate, and the actual effect of the leak test (ie whether there are leaks) is more visualized.

 

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