ISO 11117:2019

Overview

ISO 11117:2019 specifies requirements for valve protection caps and valve guards used on gas cylinders for liquefied, dissolved or compressed gases. The standard covers design, construction and type tests for devices that provide the primary mechanical protection of cylinder valves (including valves with integral pressure regulators - VIPRs) during handling, transport and storage. It excludes small cylinders (water capacity ≤ 5 L), devices permanently welded or brazed to the cylinder, and breathing-apparatus cylinder protection.

Key topics and technical requirements

• Design and fitment: minimum clearances and recommended thread forms (W 80 × 1/11 is a commonly used fixing), examples of cylinder neck ring dimensions, and guidance on rotational vs non‑rotational valve guards.
• Venting and drainage: valve protection caps must provide venting equivalent to a cross‑sectional area of at least 157 mm² for typical conventional cylinder valves (e.g., two or more vent holes ≥ 10 mm diameter) and consider water drainage.
• Mechanical strength and protection: caps and guards shall be of adequate strength and fixed to prevent inadvertent removal; designs fixed only to valves must ensure they do not promote unscrewing of the valve.
• Type testing: defined tests include preliminary checks, torque test, vertical pull test (formerly axial test), and drop test with specified acceptance criteria. Test samples, documentation and test reports are required.
• Marking and documentation: requirements for marking devices and preparing test reports; the standard clarifies marking such as "ISO PA" usage and test report content.
• Materials and compatibility: material selection and construction to withstand expected service and transport conditions.

Applications and who uses it

• Manufacturers and designers of valve protection caps and valve guards for gas cylinder manufacturers.
• Quality and compliance teams performing type testing and producing test reports.
• Testing laboratories validating caps/guards to meet transport and safety requirements.
• Cylinder packagers, shippers and transport regulators who need to ensure valve protection meets UN/transport rules.
• Equipment specifiers for industrial gas suppliers, medical gas distributors and welding-gas companies.

Related standards

• ISO 10286 - Gas cylinders: terminology.
• ISO 10297 - Gas cylinder valves: specification and type testing (including valve impact tests referenced when guards are fixed only to valves).
• UN Model Regulations - ISO 11117:2019 is written to be suitable for reference in transport regulations.

Keywords: ISO 11117:2019, valve protection caps, valve guards, gas cylinders, design, construction, drop test, W 80 × 1/11, type testing, valve protection, transport safety.