Agricultural Anhydrous Ammonia Storage Tanks with Missing/ Illegible Data Plates - PUB4003

This fact sheet is intended to provide guidance to the agricultural anhydrous ammonia regulated community regarding anhydrous ammonia storage vessels with missing or illegible data plates. This fact sheet is not intended to enact policy for the Department of Natural Resources, nor shall it serve as a means for determining compliance with state or federal regulatory requirements.

The Compressed Gas Association Standard CGA G-2.1-2023 states that anhydrous ammonia storage vessels with missing or illegible data plates, that aren’t replaceable through the manufacturer, must be inspected or removed from service by January 1, 2030. The inspection criteria cited in the CGA are as follows:

• Wall thickness of the container shell and heads in inches or millimeters.
• Water capacity of the container in pounds, kilograms, gallons, or cubic meters at 60 ºF.
• Outside surface area of the container in square feet or square meters.

Relocation of an existing storage vessel shall meet the data plate requirements and construction rules listed in the CGA. Facilities should refer to the decision tree below for guidance. If a facility determines the storage vessel does not meet relevant codes, the following tests are required:

• Testing for weld defects.
• Wall thickness of the container shell and heads in inches or millimeters.

The department interpretation of this requirement is that a storage container with missing or illegible data plates may continue to be used beyond January 1, 2030, if an inspection meeting the above criteria is performed. Facilities with anhydrous ammonia tanks that have missing or illegible data plates should contact the department's Agricultural Anhydrous Ammonia Unit for information on the inspection process.

Storage Tanks with Missing or Illegible Data Plates