Production samples are prepared for these tests by cutting external longitudinal notches, of defined dimensions, in the wall of the pipe. These notches, four of which are spaced around the circumference, act as stress concentrators and represent far in excess of any possible accidental damage to pipe whilst it is being laid.
A machine has been jointly developed by Quercus Computer Systems and a precision engineering company, which automatically cuts the test notches in samples of pipe. The operator merely has to input the dimensions of the test sample, it's wall thickness and the type of test to be carried out. The computer calculates the required machine movements, based on stored test specifications, to produce the required length and depth of notch for the particular test.
These machines are now in use at several locations in the UK, and also in Sweden, Portugal and India.