NBBI NB23-2021 Part 4 PDF

The NBIC recognizes three important areas of post-construction activities where information, understanding, and following specific requirements will promote public and personal safety. These areas include:

Installation
Inspection
Repairs and Alterations

The NBIC provides rules, information, and guidance for post-construction activities, but does not provide details for all conditions involving pressure-retaining items. Where complete details are not provided in this code, the code user is advised to seek guidance from the Jurisdiction and from other technical sources.

The words shall, should, and may are used throughout the NBIC and have the following intent:

Shall - action that is mandatory and required.
Should - indicates a preferred but not mandatory means to accomplish the requirement unless specified by others such as the Jurisdiction.
May - permissive, not required or a means to accomplish the specified task.