FP McCann recommends the use of inflatable stoppers when air testing concrete pipes. Associated test equipment should be in good condition and in full working order. FP McCann recommends that this test is done every 2-3 pipes before backfilling, regularly following the backfill during the installation and then at the finish; preferably before both manholes have been constructed.
The pipeline should be pressurised with air until ‘U’ gauge (manometer) indicates 100mm. Allow a minimum of 5 minutes for stabilisation of the air pressure, longer may be needed in cold or very hot weather. Observe the fall in indicated pressure over a 5 minute test period. The test is successful if the residual pressure does not fall below 75mm within the 5 minute test period.
If the pressure falls sharply and the pipeline appears to have failed, the following checks should be carried out:
- Inspect the seal of the inflatable stopper against the inside of the pipe using soapy water. Use pipe lubricant or industrial soap to assist in providing a seal where necessary
- Check the connections, rubber tube and stoppers for leaks
- Temperature and humidity changes can significantly affect the test. It may be necessary to allow more time for stabilisation or repeat the test in extreme weather conditions
If difficulties are still being experienced following these checks, please contact FP McCann for further assistance.
Please note that failure to adhere to the advice given above may result in any subsequent claims being invalid. Call-out charges may also apply if FP McCann’s technical personnel have to attend on-site.
Failure to successfully pass an air test does not prohibit the acceptance of the pipeline if a successful water test can be obtained in accordance with BS EN 1610.