Standards Development

Scope

This document specifies design, type test methods, marking and instruction requirements for cylinder valves with integrated pressure regulators (VIPRs) intended to be fitted to gas cylinders, pressure drums or tubes or used as a main valve for cylinder bundles that convey compressed, liquefied or dissolved gases.

These are requirements for VIPRs that are in addition to those given in the relevant closure standard, e.g. in ISO 10297 for cylinder valves, in ISO 17871 for quick-release cylinder valves, in ISO 17879 for self-closing cylinder valves and in ISO 23826 for ball valves.

NOTE 1 If the pressure regulating system of a VIPR is acting as the primary valve operating mechanism, it is covered by the relevant closure standard, e.g. ISO 10297, ISO 17871, ISO 17879 and ISO 23826. This also includes designs where closure of the primary valve operating mechanism of a VIPR is obtained by closing the seat of the pressure regulating system.

NOTE 2 If the primary valve operating mechanism of a VIPR is located at the low pressure side of the pressure regulating system, it is covered by the relevant closure standard, e.g. ISO 10297, ISO 17871, ISO 17879 and ISO 23826.

This document does not apply to VIPRs for:

• medical applications (see ISO 10524-3),

• liquefied petroleum gas (LPG) and

• cryogenic applications.

NOTE 3 Additional requirements for a VIPR with a residual pressure device are specified in ISO 15996.

NOTE 4 Additional requirements for pressure relief valves can exist in international/regional regulations/standards.

Purpose

During the preparation of the revision of ISO 22435 it was noted that a clearer separation is necessary regarding which requirements are to be given in a closure standard (like ISO 10297) and which specific requirements are to be given in the VIPR standard ISO 22435. Such a restructuring will make both standards more user friendly because it will eliminate several instances of cross-referencing, and it will be a step forward in the direction of a possible harmonization of ISO 22435 as standard for industrials VIPR and ISO 10524-3 as standard for medical VIPR, thus also creating benefit for the user, the test houses and the manufacturers.

As a result a revision of both standards, ISO 10297 and ISO 22435, was believed necessary. WG 6 unanimously agreed that the revision of both documents shall be performed in parallel.

For both documents drafts were developed by WG 6, and it was also unanimously agreed by WG 6 that after successful adoptions as new work items both document should go immediately for CD ballot.

Consider the following: Is there a verified market need for the proposal? What problem does this standard solve? What value will the document bring to end-users? See Annex C of the ISO/IEC Directives part 1 for more information. See the following guidance on justification statements on ISO Connect:

https://connect.iso.org/pages/viewpage.action?pageId=2759086