DOT Specifications 4B, 4BA, 4BW, or 4E · volumetric expansion testing · protected externally by a suitable corrosion-resistant coating and used exclusively for non-corrosive gas that is commercially free from corroding components

For DOT Specifications 4B, 4BA, 4BW, or 4E, test or inspection is volumetric expansion testing; condition or service qualifier is protected externally by a suitable corrosion-resistant coating and used exclusively for non-corrosive gas that is commercially free from corroding components; interval is every 12 years instead of every 5 years; regulation section is 49 CFR § 180.209, recorded from its source on 2026-08-06; source re-checked 2026-09-30.

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 cylinder made in conformance with DOT Specifications 4B, 4BA, 4BW, or 4E protected externally by a suitable corrosion-resistant coating and used exclusively for non-corrosive gas that is commercially free from corroding components may be requalified by volumetric expansion testing every 12 years instead of every 5 years.

— law.cornell.edu, retrieved 2026-08-06

Source

• law.cornell.eduhttps://www.law.cornell.edu/cfr/text/49/180.209

Last verified against source: 2026-09-30. Due for re-check by 2027-09-30. This page as Markdown · OKF bundle · full dataset as JSON.