http://slideplayer.com/4139729/13/images/45/Hydrotest+Methods+Constant+pressure+test+%28No+water+loss%29+%E2%80%93+DICL%2C+MSCL%2C+GRP+%26+PVC.+Constant+pressure+test+%28water+loss%29+%E2%80%93+PE%2C+ABS%2C+PP+%26+PB..jpg