Standards Development

Scope

This PAS provides recommendations for large hydrogen-fired equipment for use in industrial and commercial settings. The PAS covers the safety, design, construction, testing and performance of large hydrogen-fired equipment for use in industrial and commercial settings which are either:

•           manufacturer-purpose built;

•           manufacturer-converted; or

•           retrofit-converted to use hydrogen.

This PAS covers pre-conversion, the conversion procedure, and post-conversion processes.

This PAS applies to:

•          equipment with an input power rating exceeding 70 kW; and

•          gas pressure systems with a maximum operational gas pressure of 7 bar downstream from the first stage pressure reduction.

NOTE The 7 bar limit facilitates effective gas odorization for leak detection and reduces the risk of hydrogen embrittlement or hydrogen attack in the materials.

This PAS does not cover:

•           appliances covered by PAS 4444:2020+A1:2021;

•           gas-turbines;

•           appliances covered by the Essential Requirements of (EU) Gas Appliance Regulations[1]); or

•           Ecodesign & Energy Labelling[2]).

The PAS is for use by original equipment manufacturers (OEMs) and designers of large hydrogen-fired equipment, installers, commissioning and maintenance engineers.

It might also be of interest to Notified Bodies, insurers/underwriters, and UK competent authorities (HSE, EA).