The product certification scope of the PED Directive covers pressure equipment. The term "pressure equipment" refers to equipment whose primary design parameter is pressure, including vessels, heat exchangers, pressure piping, safety accessories, pressure accessories, and complete sets of pressure equipment with specific functions assembled from the above types of equipment (such as buffer tanks, forgings, pipe fittings, boilers, thermal power stations, etc.). Its scope ranges from small pressure cookers to large thermal power stations, covering approximately more than 10,000 product types in Europe.

PED certification is fully named Pressure Equipment Directive Certification. It is a mandatory regulation issued by EU member states after reaching a consensus on the safety of pressure equipment. Formulated for safety, health and environmental protection purposes, it aims to eliminate trade barriers and ensure the free movement of products. The CE marking is a typical symbol of EU PED certification, indicating compliance with the requirements of relevant directives and allowing products to enter and be put into service on the European market freely.

The EU Pressure Equipment Directive has been updated from the old Directive 97/23/EC to 2014/68/EU, with the new directive fully mandatorily implemented in July 2016.

• Module A1 is replaced by Module A2, which adds requirements for random inspections by Notified Bodies. Notified Bodies may conduct sampling tests at any stage of the production process.

• Under the old directive, Module B and Module B1 referred to type examination and design assessment respectively; these two modules are unified into a single Module B under the new directive.

• Module C1 is revised to Module C2, which also expands the supervision authority of Notified Bodies.

The available module selections for products after the revisions are as follows: