Pressure Equipment Directive

For process plants, the pressure equipment directive 2014/68/EU, shortened to PED, is relevant for the sizing and procurement of vessels and pipes. Vessels and pipes with a design pressure of more than 0.5bar above the atmospheric pressure of 1.013bar(a) are divided into five categories based on a pattern defined by the PED. Depending on the category, the production process must be monitored by given conformity assessment procedures. The category assignment depends on several factors. Vessels and pipes are treated differently. The design pressure is taken into account, as well as, in the case of vessels, the volume, or, in the case of pipes, the nominal diameter. The process media is classified as either dangerous or not dangerous, and as either gaseous or liquid. Liquids with a vapour pressure at the maximum possible temperature of more than 0.5bar above the atmospheric pressure of 1.013bar(a) are treated as gaseous.

The ranking according to the PED is taken into account during the sizing of the components already, as a higher ranking into the categories of the PED means higher procurement costs due to the more elaborate conformity assessment procedures required for the manufacturing process.