Pressure test unit for test leakage on plastic pipes in series production up to max. diameter D 32 mm and a max. specimen lenght of 500 meters. For the compressed air supply a compressor with 40 bar and at least 600 l/min. for dry and not oiled air is required. Also for each pipe size a pair of endclosures is necessary. Equipped with IptCompBase® Computer with 12,1‘‘ touch screen interface to IptDataLogging®, printer connection for printing test protocol. The internal diameter of the test sample (coil) is checked before the pressure test. For this purpose, a ball is blown through the test sample using compressed air. When the internal diameter is larger than the test ball, the ball is detected at the end of the test sample in a ball container and the pressure test can commence. When the internal diameter is smaller than the test ball in some places, the test ball gets stuck. The position of the test ball can then be detected with the ball detecting device. This requires a coiling machine. The test sample is cut next to the test ball in order to remove the test ball. The customer must ensure the reliable protection (e.g. with a burst chamber) of the operators during the test.