NF EN ISO 9090

Gas tightness of equipment for gas welding and allied processes

This document specifies the maximum external gas leakage rates which are acceptable for equipment used for welding, cutting and allied processes and provides the procedures of measurement.

It applies to individual components which are used in the gas supply to a blowpipe from the connecting point of the hose (outlet of the cylinder valve or connecting point to a gas supply plant). It does not apply to gas supply plant.

NOTE Specific requirements on the test method and conditions/procedure for measurement of the maximum external leakages can be given in individual standards, e.g. ISO 9012 for air-aspirated hand blowpipes. Concerning the method and the conditions to be applied, the individual standard takes precedence over this document. The maximum external leakages according to this document apply.

To comply with a standard, you need to quickly understand its issues in order to determine its impact on your activity.

The Requirements department helps you quickly locate within the normative text:
- mandatory clauses to satisfy,
- non-essential but useful clauses to know, such as permissions and recommendations.

The identification of these types of clauses is based on the document “ISO / IEC Directives, Part 2 - Principles and rules of structure and drafting of ISO documents ”as well as on a constantly enriched list of verbal forms.

With Requirements, quickly access the main part of the normative text!

The Redline + service - standards comparator allows you to easily and simply identify major changes between the current standard and its last canceled version.

At a glance, you will be able to identify the additions, deletions or modifications to a text, table, figure and formula.


The Redlines + service is offered to you on the collection of French standards in force, in French language and in HTML and PDF format.

For an overview of the service, click on View a standard in redline format

COBAZ is the simple and effective solution to meet the normative needs related to your activity, in France and abroad.

Available by subscription, CObaz is THE modular solution to compose according to your needs today and tomorrow. Quickly discover CObaz!

Request your free, no-obligation live demo

I discover COBAZ