Scope and purpose

Cryogenic enclosures can create potential process safety hazards. This publication identifies the general hazards, and provides guidance to reduce their frequency and consequences. It provides safety guidance and addresses design and operating practices only as they affect safety.

This publication addresses both cryogenic air separation unit (ASU) and HYCO processes. A number of existing publications cover special requirements of these processes and their equipment [1, 2, 3, 4, and 5]. This publication does not cover the following:

– Design and operating practices that only improve efficiency or cost;

– Generally accepted engineering practice for structures and process equipment; only those issues that are specific to cryogenic enclosures are included;

– Consequence analysis of the potential safety hazards; or

– Enclosures for processes producing liquid hydrogen or helium.

The extreme cold temperatures of these processes require specialized knowledge and practices, which are beyond the scope of this publication. This publication is primarily to document current practices and is intended to apply to new facilities. It is recognized that some existing plants may not meet all recommendations or requirements from this publication. This publication need not be applied retroactively, including where this publication uses the word "shall".