scope:

This publication will identify actions for the owners and operators of HYCO plants (including carbon monoxide and syngas plants) in response to the updated guidance on the HTHA mechanism documented in API RP 941 [1]. The guidance in CGA H-16 can apply to all scales of hydrogen production and consumption facilities that utilize the relevant materials of construction.

Risk of the HTHA mechanism will be determined for the components that are exposed to hydrogen-containing gas at a temperature above 400 °F (205 °C) (with some margin below 400 °F [205 °C] to allow for uncertainties). Examples of services in a HYCO plant that would typically require assessment are provided in Section 8.

It should be noted that there are other industries that operate hydrogen or syngas producing plants for purposes other than hydrogen production. For example, the ammonia and methanol industry operate syngas production facilities and should find relevant guidance from this publication.

This publication is not intended to address the details of design or construction of new facilities relative to HTHA. Please note that in this publication, the term "low alloy steels" refers to chromium-molybdenum (CrMo) steels.