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•  What is the reason for selecting the correct pressure class?

The criteria for choosing the correct pressure class is established in the standard EN-805: "Water supply - Requirements for systems and components outside buildings".

The pipe system designer must calculate all the conditions that affect a water network, including static and transient effects, to obtain the basic parameters, as for example, the allowable operating pressure (PFA) and the allowable maximum operating pressure (PMA)

After calculations, the designer will choose between the several classes that are possible in rigid PVC pipes.

The pressure classes for rigid PVC pipes are defined in the standard EN 1452: "Plastic piping systems for water supply. PVC-U" and the pressure classes for PVC-O pipes are defined in ISO 16422: "Pipes and joints made of oriented unplasticised Polyvinyl chloride for the conveyance of water."

The following classes are available for PVC piping and; the most used in Europe are for PVC-U 10 and 16 and for PVC-O 16 and 25: