The PED Category calculator for piping is a useful tool to calculate the category. Once the category is determined, the conformity assessment module can be selected.

Note 1: Piping means piping components intended for the transport of fluids, when connected together for integration into a pressure system; piping includes in particular a pipe or system of pipes, tubing, fittings, expansion joints, hoses, or other pressure-bearing components as appropriate;

Note 2: The heat exchangers consisting of pipes for the purpose of cooling or heating air shall be considered as piping;

Note 3: Half-pipe coil or a similar “jacket” construction that heat or cool a vessel are to be classified as vessels, therefore not a “piping”.

Note 4: Discharge piping from a pressure safety accessory, which will be exposed to a pressure PS above 0,5 bar, is in the scope of PED when exhausting to ambient atmosphere.

Note 5: Flare tip at the end of piping is in the scope of the PED. 

Note 6: Turbine piping defined as “connecting lines between different casings of the turbine train and connecting line between two positions at a single turbine casing and internal piping” is in the scope of PED, if the category is grater than I.

Note 7: Piping for super-heated water is covered at annex II table 7.

Note 8: Heat exchangers which consist of straight or bent pipes which may be connected by common circular header(s) made also from pipe are classified as piping if, and only if, the three following conditions are met: 1. air is the secondary fluid; 2. they are used in refrigeration systems, in air conditioning systems or in heat pumps; 3. the piping aspects are predominant.