Methods will be outlined which allow the calculation of the load‐bearing capacity of circumferentially cracked pipes. The reliability of the calculating procedures are checked by means of appropriate tests with pipes (DN 400) under internal pressure and with a superimposed bending moment. The loading conditions may be static as well as cyclic. The cyclic crack growth experiments were performed at the HDR test facility. Under quasistatic loading conditions the failure behaviour of pipes with through‐wall cracks were calculated on the safe side. The cyclic experiments showed the decisive influence of the environmental conditions on the crack growth rate.