CSA/ANSI HGV 4.1:20 Standard for hydrogen-dispensing systems.
6 Type testing 6.1 General These are qualification tests to evaluate a design. Changes to the initial design require evaluation by the third-party certification organization and testing, as deemed necessary. 6.1.1 The performance of a compressed hydrogen gas- -dispensing system shall meet the applicable requirements when tested as described herein. During these tests, the dispensing system shall be operated according to the manufacturer’s instructions. 6.1.2 Representative samples of a dispensing system and its component parts are subjected to the tests described in these requirements. 6.1.3 Test gas as specified in these requirements shall be a hydrogen for leak tests; b hydrogen for permeation; c) liquids (e.g., water or oil) for hydrostatic strength tests; and d) hydrogen, helium, nitrogen, or dry air for all other tests. 6.1.4 All tests shall be conducted with the inlet pressure maintained at the manufacturer’s specified maximum allowable working pressure, unless otherwise specified. Use of hydrogen and required test pressure for tests related to the protection parameter requirements shall be at the discretion of the testing agency. Note: This requirement does not apply to the vehicle- -dispenser interface, dispenser ground continuity, dielectric voltage-withstand, rain, marking material adhesion, and legibility tests.
6.2 Strength test   6.2.1 General A strength test shall be performed on the piping assemblies. Gas-containing components shall be tested either pneumatically or hydrostatically as per the clauses below. Liquid-containing components shall be tested hydrostatically only. There shall be no rupture, fracture, deformation, or other physical damage. Note: The test methods in Clauses 6.2 and 6. 3 are intended to test the strength integrity of the assembly(ies) to the requirements in ASME B31.3 and the ASME Boiler and Pressure Vessel Code. The methods below provide one method compliant to these Codes. Alternative methods detailed in ANSI/ASME B31.3 or the ASME Boiler Pressure Vessel Code can be substituted, as determined by the manufacturer and an NRTL. In Canada, strength test complies with the requirements of the appropriate clause of CAN/BNQ 1784-000 and CSA B51. 6.2.2 Pneumatic strength test General The HFS shall be tested to 110% of the design pressure when tested with nitrogen or other non-reactive gases that will not contaminate process piping and components. Notes: Pneumatics strength testing is the preferred method for hydrogen-containing components to minimize risk of contamination. Hydrostatic testing can be substituted at the request of the manufacturer, provided that the manufacturer has adequate procedures to verify that all liquid water content is removed after testing. 2) Failure during pneumatic testing can create serious damage and, possibly, deaths. Method of test Prior to conducting this test, it shall be established which components are subject to the same internal pressure during normal operation of the dispenser system. These components shall comprise an individual test section that shall be pressurized separately and, when deemed necessary, isolated from the rest of the dispensing system. A suitable pressurizing system, capable of supplying a gaseous medium at the required test pressure, shall be connected to the inlet of the test section of the dispenser system. CSA/ANSI HGV 4.1 pdf download.