EN ISO 11117:2019/FprA1

EN ISO 11117:2019/FprA1 is Amendment 1 to the gas cylinder standard for valve protection caps and guards. CEN prepared this amendment to update the design, construction and test provisions that apply to protective devices for gas cylinder valves. In practice, it matters to manufacturers, test laboratories and specifiers who need the current thread dimensions, drawing rules and re-evaluation triggers.

What does EN ISO 11117:2019/FprA1 specify?

EN ISO 11117:2019/FprA1 specifies changes to EN ISO 11117:2019 for gas cylinders fitted with valve protection caps and valve guards. The amendment focuses on how these parts are described, dimensioned and re-evaluated when the protected valve design changes.

The document is organized as targeted replacements to clause 4.3, clause 7.1, clause 7.2, clauses 7.7.8 and 7.7.9, and clause 9. The main technical content is the replacement of Figure 5 and Tables 3 and 4, which deal with typical North American threads and their tolerances.

What are the key requirements of EN ISO 11117:2019/FprA1?

EN ISO 11117:2019/FprA1 updates the thread geometry and the rules for assessing dimensional information and test repeatability. The practical effect is that design records, drawings and test decisions for valve protection caps and guards must follow the revised wording and dimensions.

Updated North American thread data in 4.3

Clause 4.3 replaces Figure 5, Table 3 and Table 4 with revised information for typical North American threads. Table 3 gives the dimensions in millimetres, including the cylinder neck ring and the valve protection cap or valve guard thread profiles, while Table 4 gives the tolerances.

For manufacturers and inspectors, this is the section used to check whether the thread form on the cap or guard matches the cylinder neck ring. It matters because thread mismatch affects fit, interchangeability and safe installation.

Maximum dimensions and dimensional envelope in 7.1 and 7.2

Clause 7.1 now distinguishes between maximum dimensions and a maximum dimensional envelope. Clause 7.2 e) 2) requires the external dimensions of valve guards, including at least L and R and the arrangement of physical features, to define the dimensional envelope, for example by a schematic drawing.

In practice, a simple size list is not enough for valve guards. The design information must show the full outer envelope and the way physical features shape it, so that drawings and verification documents describe the guard consistently.

Re-evaluation after valve design changes in 7.7.8 and 7.7.9

Clauses 7.7.8 and 7.7.9 clarify when changes to the valve design require further evaluation and possibly repetition of the drop test. For valve protection caps and valve guards, changes such as material, connections and handwheel do not automatically require further evaluation.

For valve guards, adding or changing the position, arrangement or orientation of physical features on the protected valve, compared with the original test valve, requires further evaluation to decide whether the drop test has to be repeated. Clause 7.7.9 extends this to additional valve design changes and again ties the decision to whether the drop test must be repeated.

Editorial update in clause 9

Clause 9 revises the list of indents by removing b) and c) and renumbering the following items. This is mainly a structural update, but it matters for anyone citing the clause or tracking the amended numbering.

What terms does EN ISO 11117:2019/FprA1 define?

• Valve protection cap - the protective cap used to shield the valve on a gas cylinder.
• Valve guard - the protective guard used to shield the valve on a gas cylinder.
• Cylinder neck ring - the threaded cylinder feature that mates with the cap or guard threads.
• Dimensional envelope - the external space defined by the guard dimensions and the arrangement of its physical features.
• Drop test - the test referenced in clause 7.7 to decide whether a changed design needs further evaluation.
• North American threads - the thread form shown in Figure 5 and detailed in Tables 3 and 4.

Who uses EN ISO 11117:2019/FprA1?

EN ISO 11117:2019/FprA1 is used by manufacturers of gas cylinders, valve protection caps and valve guards. It is also used by valve designers, test laboratories and conformity assessment teams that check fit, dimensions and test decisions.

Quality managers and buyers use it when specifying protective hardware for gas cylinders and when comparing a product design against the current thread and evaluation rules. It is especially relevant in the gas cylinder and valve supply chain.

What changed in EN ISO 11117:2019/FprA1 from the previous edition?

EN ISO 11117:2019/FprA1 amends EN ISO 11117:2019. The amendment replaces the North American thread figure and tables, clarifies the wording on maximum dimensions and dimensional envelopes, and revises the text on when valve design changes require further evaluation and possible repeat of the drop test. It also updates the numbering in clause 9.

Which standards are used with EN ISO 11117:2019/FprA1?

• EN ISO 11117:2019 - the parent document that this amendment updates.
• ISO 11117:2019/FDAM 1:2026 - the ISO parallel amendment referenced in the title.

What does the EN ISO 11117:2019/FprA1 document contain?

EN ISO 11117:2019/FprA1 contains replacement text rather than a full reprint of the standard. Its technical content is concentrated in one amended figure and two amended tables for North American threads, plus revised clauses on dimensional description and test re-evaluation.

The document also includes updated wording that affects how valve changes are judged against the drop test requirement. For readers working on design verification or conformity assessment, the key items are Figure 5, Tables 3 and 4, and the revised text in clauses 7.1, 7.2, 7.7.8 and 7.7.9.