EN ISO 4126-1:2013 PDF

Overview

EN ISO 4126-1:2013 - Safety devices for protection against excessive pressure - Part 1: Safety valves (ISO 4126-1:2013) is a CEN-endorsed product standard that specifies general requirements for safety valves regardless of the fluid handled. It applies to safety valves with a flow diameter of 4 mm and above and set pressures of 0.1 bar gauge and above. No temperature limitation is imposed. This standard is a product standard (not an installation/application standard) and is part of the ISO 4126 series on pressure protection devices.

Key topics and technical requirements

EN ISO 4126-1:2013 covers fundamental design, testing and marking requirements. Major topics include:

• Design requirements
  • General construction, valve end connections, minimum spring requirements and materials.
  • Definitions of valve types (direct-loaded, assisted, supplementary-loaded) and set pressure concepts.
• Production testing
  • Purpose and general procedures for hydrostatic testing, pneumatic testing, adjustment of set (cold differential) pressure and seat leakage tests.
• Type testing
  • Tests to determine operating characteristics, flow characteristics, and to determine and certify the coefficient of discharge.
• Performance determination and sizing
  • Procedures to determine safety valve performance and inputs for sizing calculations (see ISO 4126‑10 for two‑phase sizing where applicable).
• Marking and sealing
  • Required marking information and guidance on sealing of safety valves for traceability and regulatory compliance.
• Normative relationships
  • Annex ZA clarifies the relationship between EN ISO 4126-1:2013 and the European Pressure Equipment Directive (PED, 97/23/EC) for conformity presumption within the scope of the standard.

Practical applications and users

Who uses EN ISO 4126-1:2013:

• Valve manufacturers - to design and certify safety valves for sale in markets recognizing EN/ISO standards.
• Test laboratories and certification bodies - to perform production and type testing and certify discharge coefficients.
• Pressure vessel and system designers - to select compliant safety valves based on product performance data.
• Safety and compliance engineers, procurement teams and inspectors - to verify markings, test records and conformity with PED where applicable.

Practical benefits:

• Provides consistent criteria for safety valve performance, testing and traceability.
• Supports product certification and regulatory acceptance across CEN member states.

Related standards

EN ISO 4126 is a multipart series. Relevant parts include:

• ISO 4126-2 (bursting disc devices), -3 (combined devices), -4 (pilot-operated valves), -5 (CSPRS), -7 (common data), -10 (sizing for two‑phase flow), -11 (performance testing). Refer to ISO 4126-7 for common data used across parts.