SIST 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.