In order to increase the quality of pipes made of PP the polymorphism of PP can be used. The present work aims to verify the assumed influence of processing conditions on the morphology by simulating the cooling behavior of an extruded pipe with a common FE-program and evaluating the resulting degree of crystallinity. The heat transfer coefficients needed have been taken from literature. Measurements of the surface-temperature during extrusion of pipes are in well agreement with the results of the simulation. To offer the operator an inexpensive estimation of the crystallization behavior, the used model bases on a single test. First comparisons of the simulated values with WAXD-measurements show a qualitatively well agreement. Several measurements indicate at least one additional influencing parameter for the impact behavior identified as internal stresses. To get an idea of the influence of this parameter a stress analysis has been added. The computed behavior reflects the reality qualitatively well. Further investigations are intended to get a more detailed insight in the stress behavior of pipes and to improve the quantitative agreement of the simulation. All results of this work underline the influence of the processing conditions as well as the material impact on the final behavior of the produced pipe and show that further research work is required to clarify interrelations and additional parameters.