CGA C-3-2019 PDF

Full title and description

CGA C-3-2019 — Standard for Welding on Thin‑Walled Steel Cylinders. This Compressed Gas Association (CGA) standard establishes requirements for welding procedures, operator qualification, and radiographic inspection for welded steel compressed gas containers manufactured to U.S. Department of Transportation (DOT) and Transport Canada (TC) specifications, with the objective of promoting uniformity and serviceability of such containers.

Abstract

CGA C-3-2019 (8th edition) addresses specific production welding techniques for thin‑walled steel cylinders used as compressed gas containers. It defines parameters for material gauges (thickness), welding procedure and operator qualification, and radiographic inspection practices for containers meeting specified service pressure, capacity and wall‑thickness limits. The standard is not intended to cover every welding situation; where techniques fall outside the scope of this document, ASME Boiler and Pressure Vessel Code Section IX is referenced for welding and brazing qualification guidance.

General information

• Status: Published / active (8th edition).
• Publication date: 05/01/2019 (May 1, 2019).
• Publisher: Compressed Gas Association (CGA).
• ICS / categories: Standards for compressed gas containers, welding and inspection (industry category: compressed gas equipment and cylinder manufacture). (ICS not explicitly listed in the publisher product entry.)
• Edition / version: 8th edition (designation CGA C-3-2019).
• Number of pages: 32 pages.

Scope

This standard applies to DOT and TC specification welded steel compressed gas containers with a maximum service pressure of 900 psi (62.1 bar), a maximum water capacity of 454 kg (1000 lb) and a maximum wall thickness of 0.375 in (9.53 mm). It covers production welding techniques, qualification of welding procedures and operators, and radiographic inspection criteria for those containers. It does not attempt to cover all welding situations; alternative or exceptional techniques should be evaluated in reference to ASME Boiler and Pressure Vessel Code Section IX.

Key topics and requirements

• Welding procedure specification (WPS) elements for thin‑walled steel cylinder fabrication.
• Operator qualification criteria and documentation requirements.
• Radiographic inspection standards and acceptance criteria for welds.
• Material thickness (gauge) limits and their influence on allowable welding variables.
• Interface with regulatory DOT/TC specifications for cylinders and reference to ASME Section IX for variables outside the document’s detail.

Typical use and users

Used by cylinder manufacturers, welding engineers, quality/inspection personnel, regulatory compliance officers, and third‑party auditors/inspectors who are responsible for fabrication and inspection of welded steel compressed gas cylinders produced to DOT/TC specifications. The standard supports production control, operator training/qualification, and non‑destructive testing acceptance decisions.

Related standards

Related documents and references commonly consulted with CGA C-3 include ASME Boiler and Pressure Vessel Code Section IX (Welding and Brazing Qualifications) for essential variables and material types, other CGA cylinder and inspection standards (e.g., visual inspection and periodic inspection standards), and DOT/TC regulatory specifications for cylinder design and transport.

Keywords

welding; thin‑walled steel cylinders; compressed gas cylinders; operator qualification; radiographic inspection; DOT; Transport Canada; ASME Section IX; welding procedure specification.

FAQ

Q: What is this standard?

A: CGA C-3-2019 is the Compressed Gas Association’s standard titled "Standard for Welding on Thin‑Walled Steel Cylinders" (8th edition), specifying welding, qualification and inspection requirements for certain welded steel compressed gas containers.

Q: What does it cover?

A: It covers production welding techniques, welding procedure and operator qualification, and radiographic inspection acceptance for welded steel cylinders meeting the stated service pressure, capacity and wall‑thickness limits. The document is not exhaustive for all welding types and refers users to ASME Section IX where broader welding qualification rules are needed.

Q: Who typically uses it?

A: Cylinder manufacturers, welding supervisors, quality/inspection personnel, third‑party inspectors, and regulatory compliance staff involved in the manufacture and inspection of DOT/TC specification welded steel compressed gas cylinders.

Q: Is it current or superseded?

A: The publication date is May 1, 2019 (8th edition). Publisher records list CGA C-3-2019 as the 8th edition; no later edition or formal superseding revision was identified in the publisher product entry or common document distributors as of February 24, 2026. Users who require absolute confirmation for regulatory or procurement purposes should verify the current status directly with CGA or an authorized standards distributor.

Q: Is it part of a series?

A: CGA publishes many related standards covering cylinder design, inspection, valve configurations and handling. CGA C-3 is part of that body of CGA standards addressing cylinder manufacture and inspection practices and is often used alongside other CGA and industry standards (for example visual inspection and periodic inspection guidelines).

Q: What are the key keywords?

A: Welding, thin‑walled steel cylinders, compressed gas cylinders, operator qualification, radiographic inspection, DOT, Transport Canada, ASME Section IX.