CGA C-5-2022 PDF

Full title and description

St CGA C-5-2022 — "Wall Stress Requalification Criteria for High Pressure Seamless Steel Cylinders". This CGA publication provides methods and criteria for determining average wall thickness and establishing requalification limits for seamless, high‑pressure steel cylinders manufactured to DOT/ICC/TC specifications.

Abstract

This standard sets out detailed procedures for determining average wall thickness and the related rejection (service‑life) limits used when requalifying seamless high‑pressure steel cylinders (e.g., ICC-3, ICC/DOT-3A, DOT-3AX, DOT-3AA, DOT-3AAX, DOT-3T and Canadian equivalents). It includes calculation methods (indirect methods and formulae), flow charts for service‑life control, and appendices covering procedures for special filling limits. The document excludes special provisions for DOT‑3HT/CTC‑3HT/TC‑3HTM cylinders (covered by other CGA documents).

General information

• Status: Current.
• Publication date: October 6, 2022.
• Publisher: Compressed Gas Association (CGA).
• ICS / categories: ICS 23.020.30 — Pressure vessels, gas cylinders.
• Edition / version: 8th edition (2022).
• Number of pages: 22 pages (CGA product listing).

Scope

Covers methods for determining average wall thickness and establishing elastic expansion/rejection limits for requalification of seamless, high‑pressure steel cylinders used for compressed gases. The procedures apply to cylinders manufactured to common DOT/ICC specifications and to equivalent Canadian specifications; the standard references CGA C‑1 for hydrostatic testing and CGA C‑6 for visual inspection. It provides service‑life control flow charts and appendices addressing special filling limits required by DOT and Transport Canada. Cylinders manufactured to DOT‑3HT/CTC‑3HT/TC‑3HTM are excluded from the recommendations and are treated in CGA C‑8.

Key topics and requirements

• Procedures to determine average wall thickness for seamless high‑pressure steel cylinders (indirect and direct methods).
• Formulas and calculation methods referenced (e.g., Bach and Clavarino approaches) for establishing elastic expansion rejection limits.
• Flow chart for service life control (informative appendix) outlining decision steps for acceptance, special limits, and rejection.
• Guidance for qualifying cylinders for special filling limits in accordance with DOT and Transport Canada regulations (appendices).
• Reference to related CGA standards for test methods and visual inspection (notably CGA C‑1 and CGA C‑6) and an explicit exclusion for DOT‑3HT family cylinders (see CGA C‑8).

Typical use and users

Primary users include cylinder requalification facilities, gas suppliers and distributors, fleet owners, cylinder inspectors, regulatory compliance personnel, and safety engineers responsible for cylinder maintenance and return‑to‑service decisions. The standard is used to set acceptance/rejection criteria during periodic requalification and to document service‑life control procedures for high‑pressure seamless steel cylinders.

Related standards

Commonly used alongside CGA C‑1 (Methods for Pressure Testing Compressed Gas Cylinders and Tubes) and CGA C‑6 (Standard for Visual Inspection of Steel Compressed Gas Cylinders). Requalification specifics for DOT‑3HT/CTC‑3HT/TC‑3HTM cylinders are addressed in CGA C‑8. Regulatory cross‑references include the applicable sections of 49 CFR (U.S. DOT) that cite CGA guidance for cylinder service life and requalification.

Keywords

requalification, wall stress, elastic expansion, average wall thickness, seamless steel cylinders, DOT‑3A/DOT‑3AA/DOT‑3AX, ICC‑3, service life control, hydrostatic testing, volumetric/expansion methods.

FAQ

Q: What is this standard?

A: CGA C‑5‑2022 is the Compressed Gas Association's 2022 edition titled "Wall Stress Requalification Criteria for High Pressure Seamless Steel Cylinders", which provides methods and criteria for assessing wall thickness and service‑life rejection limits for seamless high‑pressure steel cylinders.

Q: What does it cover?

A: It covers calculation and test procedures used to determine average wall thickness, elastic expansion rejection limits, service‑life control procedures (flow charts), and appendices with procedures for special filling limits relative to DOT and Transport Canada requirements. It does not cover DOT‑3HT family cylinders (those are covered in CGA C‑8).

Q: Who typically uses it?

A: Cylinder requalification shops, gas producers and distributors, equipment owners, inspection and maintenance personnel, and regulators who need consistent, industry‑accepted criteria for returning high‑pressure seamless steel cylinders to service.

Q: Is it current or superseded?

A: CGA C‑5:2022 is the current edition (published October 6, 2022) and supersedes the earlier CGA C‑5 (2010) edition. Users should verify whether any amendments or later editions have been released after 2022 before relying on the standard for regulatory compliance.

Q: Is it part of a series?

A: Yes — it is part of CGA's series of cylinder inspection and requalification publications (C‑series), which also includes related documents such as CGA C‑1 (pressure testing), CGA C‑6 (visual inspection), CGA C‑8 (requalification for DOT‑3HT types), and others addressing inspection, testing, and requalification practices.

Q: What are the key keywords?

A: Requalification, wall stress, elastic expansion, rejection limits, average wall thickness, hydrostatic test, seamless steel cylinder, DOT, ICC, service life.