Overview
EN ISO 4126-1:2013/A2:2019 - Safety devices for protection against excessive pressure - Part 1: Safety valves (ISO 4126-1:2013) is a CEN-adopted amendment (A2) to the ISO standard that defines requirements for safety valves used to protect pressure equipment from overpressure. The amendment (approved 29 January 2019, published June 2019) updates Annex ZA to align the standard with the EU Pressure Equipment Directive (PED 2014/68/EU). As a harmonized European standard, it can provide a presumption of conformity with relevant PED essential requirements when cited in the Official Journal.
Key topics and requirements
This amendment refines the normative relationship between the standard and the PED and highlights several technical areas addressed in the standard:
- Safety valves: fundamental requirements for valves designed to relieve excessive pressure in pressurized systems.
- Safety accessories: clauses covering associated devices that support valve operation and safety (referenced clauses 5–9).
- Proof test: procedures and requirements for verifying valve performance (clause 6.3).
- Draining and venting: means to ensure safe draining and venting of the protected equipment (clause 5.1.6).
- Safe handling and operation: provisions to ensure the equipment can be operated and handled safely (clause 5.1.5).
- Conformity with PED: Annex ZA maps clauses to PED essential requirements (Annex I items 2.3, 2.5, 2.11.1, 3.2.2), indicating which parts of the standard support regulatory compliance.
Note: This summary reflects the amendment text and Annex ZA; users should consult the full EN ISO 4126-1:2013/A2:2019 document for detailed technical specifications and test methods.
Applications
EN ISO 4126-1:2013/A2:2019 is applied across industries that use pressure equipment and require protection from excessive pressure:
- Selection and specification of safety valves for boilers, pressure vessels, pipelines and process systems.
- Development of manufacturing and quality procedures for valve producers and safety-accessory suppliers.
- Design and installation guidance for system integrators and plant engineers to meet safety and regulatory requirements.
- Testing and maintenance planning, including proof testing and inspection regimes.
- Demonstrating conformity with the Pressure Equipment Directive (PED 2014/68/EU) for market access in the EU/EFTA.
Who should use this standard
- Valve manufacturers and component suppliers
- Pressure equipment designers and process engineers
- Safety and maintenance engineers, inspection bodies and notified bodies
- Regulatory compliance teams and technical purchasers
Related standards
- Other parts of the ISO 4126 series (safety devices for protection against excessive pressure)
- Directive 2014/68/EU (Pressure Equipment Directive, PED) - referenced in Annex ZA
Using EN ISO 4126-1:2013/A2:2019 helps organizations align safety valve design, testing and documentation with recognized international and European requirements for protection against excessive pressure.