The piping (or pipeline) describes a pipe with pumps or pump stations with which the transport of fluids or gases is handled. A piping consists of pipes, valves and gaskets, connecting elements, screw connections, expansion parts, shaped parts, and generally also compensators for absorbing movements that occur during the transport, and devices for fastening. In extreme cases, a piping can be thousands of kilometers long, such as a pipeline for delivery. The diameter of a piping is referred to as nominal diameter (abbreviated DN from the French designation diamètre nominal). The nominal diameter always refers to the inside diameter. The permissible load with respect to the internal pressure in the piping is indicated with nominal pressure (PN, pressure nominal). Not only the desired or resulting pump capacity plays a role for the dimensioning of the matching piping for operating an installation. Starting at a certain length, the speed of the flow rate as well as the NPSH conditions are also important. Depending on the maximum pressure that occurs, material and wall thickness of the pipe must be selected. In industrial installations, so-called pipe classes are used that describe an application area defined in advance. Back