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БДС EN ISO 4126-3:2021

Safety devices for protection against excessive pressure - Part 3: Safety valves and bursting disc safety devices in combination (ISO 4126-3:2020)

Jan 21, 2021

General information

60.60     Jan 21, 2021



European Standard



Appropriate for SMEs



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This document specifies only the requirements for a product assembled from the in-series combination of safety valves or CSPRS (controlled safety pressure relief systems) according to ISO 4126‑1, ISO 4126‑4 and ISO 4126‑5, and bursting disc safety devices, according to ISO 4126‑2, installed upstream of the valve within five pipe diameters of the valve inlet. It specifies the design, application and marking requirements for such products, composed of the bursting disc safety device, a safety valve or CSPRS and, where applicable, a connecting pipe or spool piece. In addition, it gives a method for establishing the combination discharge factor used in sizing combinations.

Directives and Regulations

When the standard is harmonized under a directive or regulation, the word Harmonized appear. When such an inscription does not appear, it means that the standard is related to / supporting the relevant directive or regulation.


Directive 2014/68/EU of the European Parliament and of the Council of 15 May 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of pressure equipment


Life cycle


БДС EN ISO 4126-3:2006


БДС EN ISO 4126-3:2021
60.60 Standard published
Jan 21, 2021

Related project

Adopted from EN ISO 4126-3:2020

Adopted from ISO 4126-3:2020