Structural analysis of piping systems is within the piping discipline commonly referred to as pipe stress analysis or just stress analysis. To validate the structural integrity of piping systems the piping structural engineers (pipe stress engineers) performs different types of analysis dependent on the criticality, design code, international-and national regulations, load-cases and any specially request from customers such as optimisation with regard to total assembly- weight and volume. Some piping systems are more critical and more difficult to design than others with regard to temperature variations, vibrations, fatigue and connection to sensitive equipment such as turbines and compressors. The forces and moments that a poorly designed piping system can add to the pipe support structure and connected equipment can be enormous and detrimental. Flanges may separate, hydrocarbon gases escape and mixed with air detonate if there is an ignition source. Flange leakage of condensate or diesel dripping onto a hot surface may start a fire, and for other piping systems people may be exposed to toxic fluids and gases such as hydrogen sulphide and radiation.