With the expansion of EU member states and the increase in domestic exports to the EU, an increasing number of ASME certificate holders wish to understand the specific regulations and requirements involved in Pressure Equipment Directive (PED) certification. Here is a brief introduction to several key issues of interest during the implementation of PED certification, provided for reference by relevant enterprises.

1. Selection of Product Design and Manufacturing Standards

In accordance with the non-discrimination and national treatment principles of the WTO, technical standards for products are non-mandatory in order to eliminate trade barriers and ensure the free movement of goods. However, for reasons such as safety, health, and environmental protection, governments may enact mandatory product technical regulations. The PED is a mandatory regulation promulgated by EU member states upon reaching a consensus on the safety of pressure equipment.

Comparing it simply with ASME authorization: PED certification is a safety certification for specified products, whereas ASME certification is a facility/shop authorization for specified standards. This is the primary distinction in nature between the two.

It is worth noting that in PED certification, the Essential Safety Requirements (ESRs) stipulated by the directive are mandatory, whereas the technical standards of the product are non-mandatory. Unless specified by the purchaser/user, the manufacturer is free to choose any technical standard. This differs significantly from domestic Chinese regulations, where national, ministerial, or industry standards must be strictly enforced.

Therefore, when accepting orders for products exported to the EU that require PED certification and the CE mark, enterprises should clarify the product design and manufacturing standards with the user. For pressure vessels, if the user does not specify a standard, the manufacturer may choose Chinese standards (such as GB 150). In our practice, there are certifications performed according to ASME Codes or German AD Merkblätter as specified by users, as well as certifications completed according to GB 150 as chosen by manufacturers.

2. Selection of Conformity Assessment Modules

As is well known, PED certification first requires risk categorization of pressure equipment (divided into four categories, from low to high risk: Category I, II, III, and IV). The categorization depends on the following parameters:

1. Equipment Type: e.g., boilers, pressure vessels, piping, etc.
2. Fluid Group: Divided into Group 1 (dangerous) and Group 2 (non-dangerous) according to hazard level.
3. Maximum Allowable Pressure: $PS$ (bar).
4. Volume or Nominal Size: $V$ (Liters) or $DN$ (mm).

Based on the above parameters, the hazard category of the equipment is determined using Charts 1–9.

Taking pressure vessels as an example: vessels containing Group 1 (dangerous) fluids with $PS \times V > 1000\text{ bar}\cdot\text{L}$, or Group 2 (non-dangerous) fluids with $PS \times V > 3000\text{ bar}\cdot\text{L}$, fall under Category IV. As a result, pressure vessels used in the chemical, petroleum, and petrochemical industries basically belong to Category IV.

Selection of Practical Assessment Modules

Most pressure vessels are non-standard products manufactured on a single-piece basis. Choosing the EC Type Examination module (B+D) or Design Examination module (H1) based on an ISO 9001 quality system has little practical value due to the minimal chance of repetitive manufacturing. Furthermore, without a Certificate of Conformity issued for the specific product by a Notified Body, users may lack confidence. Therefore, we usually recommend Module G (EC Unit Verification), in which routine inspections are conducted according to product standards, supervised and verified by a Notified Body, which then issues a Certificate of Conformity for the specific product.

For standardized series products that may be mass-produced (such as storage tanks, heat exchangers, etc.), we usually recommend the Module B+F (Type Examination + Product Verification) approach. Based on type approval, unit-by-unit inspection is performed on products, and a Certificate of Conformity is issued by the Notified Body to ensure quality and safety.

We only recommend selecting Module B+D or H1 for standardized series products that are mass-produced, such as valves.

According to directive provisions, manufacturers may also select a higher category of conformity assessment module to meet the demands of their production development.

3. Particular Material Appraisal (PMA)

PED certification permits the use of three types of materials:

• Materials conforming to European Harmonized Standards;
• Materials with European Approval for Materials (EAM);
• Materials approved through Particular Material Appraisal (PMA).

The claim that "Pressure equipment exported to the EU must use European standard materials or European-approved materials" is inaccurate.

It is difficult for domestic manufacturing enterprises to obtain materials produced to European harmonized standards. As for materials under other national standards (such as US ASME, Chinese GB, or YB), obtaining European approval is procedurally possible, but in practice—including mature materials in the ASME code—none have received European approval to date. Therefore, the feasible route in actual production is to conduct material appraisals through a Notified Body to obtain a Particular Material Appraisal (PMA) certificate for product manufacturing.

Conditions for Particular Material Appraisal (PMA):

1. The material used must have been confirmed as safe prior to November 29, 1999 (i.e., mature materials already used in production practice, not new material grades);
2. It must conform to existing standards or specific technical conditions;
3. It must possess a material test certificate complying with the EN 10204 standard;
4. Materials from unknown sources are not accepted.

When executing a Particular Material Appraisal, the Notified Body will audit the material application and procurement documents, material supplier evaluation files, material quality certificates, additional test records (if required), and material receiving inspection records provided by the manufacturer. A PMA certificate will be issued to the manufacturer for materials that meet the requirements.

A PMA certificate is restricted to that specific manufacturer and is invalid for other enterprises. If a material receives European Approval (EAM), all manufacturers may use it.

According to PED regulations:

• Materials for Category I and Category II equipment are subjected to Particular Material Appraisal performed by the manufacturer.
• Materials for Category III and Category IV equipment require Particular Material Appraisal executed by a Notified Body.

4. EN 10204 Material Inspection Certificates

The PED Essential Safety Requirements for material manufacturers (including castings and forgings) dictate having a suitable quality system certified by a competent body within the EU, along with specific material evaluation. Under these circumstances, a 3.1B certificate issued by the material manufacturer in accordance with the EN 10204 standard can be accepted.

A 3.1B inspection certificate under the EN 10204 standard (Metallic products - Types of inspection documents) refers to an inspection certificate signed by an authorized representative of the material manufacturer who is independent of the manufacturing department (i.e., signed by an independent quality supervision and inspection department). This is also the material certificate format widely adopted by domestic enterprises.

However, if the material manufacturer's quality system is not certified by an EU certification body, only a 3.1C certificate (signed by the purchaser's authorized representative) or a 3.2 certificate/report (jointly signed by the authorized representative of the material manufacturer independent of production and the purchaser's authorized representative) can be used.

Note on EN 10204:2004(E) revisions: The former 3.1B certificate has been replaced by the 3.1 Inspection Certificate; the former 3.1A, 3.1C certificates, and 3.2 inspection reports have been replaced by the 3.2 Inspection Certificate.

For domestic material manufacturers, the simplest way to qualify for issuing 3.1 inspection certificates is to undergo PED conformity assessment conducted by an EU inspection body. Upon verifying that their existing quality system operates effectively, the inspection body audits relevant documents executing material standards, spot-checks physical items, and issues a PED Certificate of Conformity for the material manufacturer's products upon qualification.

5. Nondestructive Testing (NDT) Personnel Qualification Approval

PED Essential Safety Requirements stipulate that non-destructive testing for permanent joints of pressure equipment must be performed by qualified personnel.

For Category III or Category IV pressure equipment, NDT personnel must be approved by a Recognized Third-Party Organization approved by the EU.

Regarding NDT personnel qualification standards, European standard EN 473 may be used, and the American Society for Nondestructive Testing standard SNT-TC-1A is also permitted.

During evaluation, enterprise NDT personnel are generally not re-examined (whether re-examination is necessary is determined by the third-party organization auditor based on the enterprise's actual situation). Instead, the audit focuses on whether the enterprise's training, examination, and management documents for NDT personnel formulated according to standards meet regulations. Based on this, on-site audits verify actual execution and witnessing documentation. Qualified applicants will receive an approval certificate issued by the recognized third-party organization covering all qualified NDT personnel of that manufacturer.

To facilitate enterprises, Bureau Veritas (BV) collaborated with the recognized third-party organization—the British Institute of Non-Destructive Testing (BINDT). Starting August 25, 2001, Level III NDT personnel from BV China act on behalf of BINDT to conduct enterprise NDT personnel qualification approvals, with approval certificates issued by BINDT to those who qualify.

6. Pressure Equipment Below Category I (Article 3, Section 3)

The scope of PED applies to pressure equipment with a maximum allowable pressure ($PS$) greater than 0.5 bar. However, besides maximum allowable pressure, its hazard categorization depends on multiple parameters such as equipment type, fluid properties, volume, or nominal diameter. Among the 9 hazard categorization charts defined in the directive, equipment falling under the scope below Category I (i.e., Article 3, Section 3 of the Directive, Sound Engineering Practice / SEP) exists in each chart. Some manufacturing enterprises have also encountered such issues when undertaking projects.