DOT 4B, 4BA, 4B240ET or 4BW · water-jacket, direct expansion or proof pressure test methods · used as a fire extinguisher, with a water capacity of 5.44 kg (12 pounds) or less
For DOT 4B, 4BA, 4B240ET or 4BW, test or inspection is water-jacket, direct expansion or proof pressure test methods; condition or service qualifier is used as a fire extinguisher, with a water capacity of 5.44 kg (12 pounds) or less; interval is by the end of 12 years after the original test date and at 12-year intervals thereafter; regulation section is 49 CFR § 180.209, recorded from its source on 2026-08-06; source re-checked 2026-09-30.
- Container specification
- DOT 4B, 4BA, 4B240ET or 4BW verified
- Test or inspection
- water-jacket, direct expansion or proof pressure test methods our reading
- Interval
- by the end of 12 years after the original test date and at 12-year intervals thereafter verified
- Condition or service qualifier
- used as a fire extinguisher, with a water capacity of 5.44 kg (12 pounds) or less
- Regulation section
- 49 CFR § 180.209
Values marked our reading are our classification of what the source says — the source does not print them in those words. The quote below is the evidence for each one; judge it yourself.
What the source says
A DOT 4B, 4BA, 4B240ET or 4BW cylinder used as a fire extinguisher may be tested as follows: (i) For a cylinder with a water capacity of 5.44 kg (12 pounds) or less, by the water-jacket, direct expansion or proof pressure test methods as prescribed in CGA C-1. A requalification must be performed by the end of 12 years after the original test date and at 12-year intervals thereafter.
— law.cornell.edu, retrieved 2026-08-06
Source
- law.cornell.eduhttps://www.law.cornell.edu/cfr/text/49/180.209