Plain-language guides for RIN holders.
The §180 series, the +/★ marks, the records that survive an audit. Written for working requalifiers, not lawyers.
Compliance
3 guidesPHMSA Audit Prep: What to Expect
What records PHMSA asks for, what they cite people for, and the prep work that turns the visit from a forensics exercise into a review.
Plus (+) and Star (★) Marks: The Definitive Guide
What each mark means, how a cylinder qualifies, when the marks come off, and the SP variations that override the standard rules.
Calibration Chains: Why Auditors Trace Your Test Equipment
From the test gauge at the bay back to NIST. The records you need, the gaps that trip facilities up at audit, and how to choose a calibration vendor.
Technical
2 guidesHydrostatic Test Math: From Service Pressure to Disposition
Test pressure formulas by spec, the elastic and permanent expansion logic, the 10% rejection threshold, and SP overrides.
Eddy Current Testing for SCUBA Cylinders: The 6351-T6 Story
Why aluminum 6351-T6 cylinders need eddy current at requalification per §180.209(m), what sustained load cracking is, and how the test works.
Coming soon
2 guidesWhat you need to get started
The exact checklist for opening a Requalify account: RIN, Special Permits, your inspector roster, and the equipment files we use.
How to apply for a RIN
The PHMSA RIN application process, what you'll need on hand, typical timelines, and what to do while you wait for approval.