Checklists: B109 vs. Appendix B (IIAR 6, Part 16)

IIAR Bulletin No. 109 (B109) has been an integral part of ammonia refrigeration vernacular for over 20 years. “B109s” have been the gold standard for annual mechanical integrity inspections since the document was published in 1997. The ten easy to understand checklists which comprise most of the document have served our industry well during this period.

ANSI/IIAR 6-2019 Appendix B includes improved checklists that aim to improve on the foundation of B109.

What has changed?

Number of Checklists

B109 included ten checklists, while IIAR 6 has twelve. Notably, new checklists have been developed for Purgers and Ammonia Absorption Systems. The Ventilation checklist in B109 has been expanded to include other safety devices and renamed Safety Systems. Some content has been moved from the B109 General Safety checklist and placed in Safety Systems, so it was fitting to rename the checklist General System.

A comparison of the titles of the checklists in the two documents is presented in the table below:


Question Phrasing

B109 checklists included several questions that were phrased in such a way that a ‘No’ answer indicated a “compliant” response, which conflicted with the column heading “Conforms”. For example, the Pressure Vessel checklist asked, “Does the pressure vessel have known/alterations or modifications?”. Often, the answer to this question is ‘No’, but due to the format of the checklist, a ‘No’ answer appears to indicate non-conformity.

IIAR addressed this confusion by ensuring that a ‘Yes’ response indicates conformity, while ‘No’ responses require correction.


Checklist Content

A noteworthy difference between B109 and IIAR 6 Appendix B is that the new checklists contain additional content that was not included in B109. It is beyond the scope of this blog to address each change, but the image below compares the air-cooling evaporator B109 checklist to the IIAR 6 checklist and highlights five new questions that have been included which inquire about leaks, pipe labeling, valve condition, valve exercising, and instrumentation.


IIAR members are provided with free access to the Appendix B checklists. You can download them by clicking this link.

This is Part 16 of a series on IIAR 6. You can access previous blogs in this series below:

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