1.1 Scope
This standard specifies uniform methods for testing and evaluating the performance of fittings for use with
compressed hydrogen gas and hydrogen rich gas mixtures. It does not address special requirements for
liquid and slush hydrogen.
This standard applies to hydrogen systems applications to meet current market needs.
In this standard, the term “fittings” includes fittings, connectors, and stud ends for ports.
This standard does not apply to stand alone components, such as:
1. Quick Action couplings, (i.e., quick connects);
2. Flanges; or
3. Welded joints.
This standard applies to newly manufactured fittings. It does not apply to fittings qualified for hydrogen
service by other relevant Nationally Recognized standards or regulations such as AFNOR, BSI, CGA, JIS, etc.
If the value for measurement as given in this standard is followed by an equivalent value in other units, the
first stated value is to be regarded as the specification.
All references to pressure throughout this standard are to be considered gauge pressures, unless otherwise
specified.2
The requirements of this standard may be superseded by an application specific standard.
The construction of parts not covered by this standard shall be in accordance with reasonable concepts of
safety, substantiality and durability.
All specifications as to construction set forth herein may be satisfied by the construction actually prescribed
or such other construction as will provide at least equivalent performance.
1.2 General
1.2.1 Material Requirements.
Materials normally in hydrogen contact shall be demonstrated to be acceptable in hydrogen service.
Materials shall be selected to minimize the risk of significant change in performance due to hydrogen
embrittlement, stress corrosion, or hydrogen-induced fatigue failure during the service life of the fitting
assembly.
Note: This standard contains no criteria for evaluation for external environmental exposure.
1.2.2 Failure Modes and Effects Analysis (FMEA).
Design FMEA and Process FMEA shall be performed for fittings. The documents shall be made available for
review on request to the certifying body.
NOTE: FMEA is a methodology used in industry to identify potentially hazardous failure modes of safety devices and
recommend changes in design, manufacturing, inspection, and/or testing that eliminate such failure modes or minimize
their effects. FMEA is applied to both device design and to the manufacturing and assembly process to identify corrective
actions that improve device reliability and safety. Available references include SAE J1739, “Potential Failure Mode and Effects
Analysis in Design (Design FMEA), Potential Failure Mode and Effects Analysis in Manufacturing and Assembly Processes
(Process FMEA), and Potential Failure Mode and Effects Analysis for Machinery (Machinery FMEA)”.
1.3 Instructions
Clear, concise, printed instructions and diagrams, stated in terms understandable and adequate for proper
assembly, installation, maintenance and operation, shall be made available by the manufacturer of the
fitting.
The information not included on the fitting shall be included with the component literature.
The certifying agency shall have the right to direct additional information be included in the instructions.
1.4 Marking
1.4.1 Marking Information.
Fittings shall be permanently marked with the following information:
a. Pressure class or rated pressure;
b. Manufacturer’s name, trademark, or symbol;
c. Heat code of the material or marking directly traceable to the material test report;
d. Type of material;
e. Designation if the fitting is a metric size instead of an inch size; and
f. Symbol of the testing organization for compliance with this standard.
When the size and shape of fittings do not permit all the above markings, they may be omitted in the
reverse order given above, provided the information is supplied in the manufacturers’ literature.
1.4.2 Marking Methods.
Markings shall be permanent. Fittings may be marked by laser, etching, stamping, molding, permanent
label, or by other means.