Michigan Administrative Code › Department - Licensing and Regulatory Affairs › Bureau of Fire Services › Storage and Handling of Gaseous and Liquefied Hydrogen Systems › Part 2 - STORAGE AND HANDLING OF GASEOUS HYDROGEN NFPA 50A › Chapter 2 - Design of Gaseous Hydrogen Systems › Section R. 29.7022 - Piping, tubing, and fittings

Current through Vol. 24-12, July 15, 2024
Rule 22. Sections 2-3.1 is reproduced from NFPA 50A, and
						sections 2-3.1.1, 2-3.1.2, and 2-3.2 to 2-3.13 of the storage and handling of
						gaseous and Liquefied H2 code are added as
						follows:
2-3 Piping, tubing, and fittings.
2-3.1 Piping, tubing, and fittings shall be suitable for
						H2 service and for the pressures and temperatures
						involved. Cast-iron pipe and fittings shall not be used.
2-3.1.1 A piping system shall be substantially supported
						and protected against physical damage and excessive stresses arising from
						settlement, vibration, expansion, or contraction. Supports for aboveground
						piping shall be constructed of noncombustible material.
2-3.1.2 Aboveground piping systems shall be protected
						from corrosion in compliance with recognized standards. Underground piping
						systems shall be in compliance with section 5-4.
2-3.2 Material specifications and thickness requirements
						for piping and tubing shall conform to ASME B31.3, "Process Piping," adopted by
						reference in section 8-1.
2-3.3 Brazing materials shall have a melting point above
						1,000 degrees Fahrenheit (538 degrees Celsius). Flanged connection shall use a
						gasket that is suitable for H2. When making joints in
						piping and tubing, thread sealants, when used, shall be suitable for
						H2 service and shall be applied to male pipe threads
						prior to assembly.
2-3.4 Aboveground piping systems shall be marked in
						accordance with the following:
(a)
					 Marking shall include the name of the gas and direction of flow
					 arrow.
(b) Marking for piping
					 systems shall be provided at the following locations:
(i) At each critical process control
					 valve.
(ii) At wall, floor, or
					 ceiling penetrations.
(iii) At each
					 change in direction.
(iv) At a
					 minimum of every 20 feet (6.1 meters) or fraction thereof throughout the piping
					 run.
2-3.5 Threaded or flanged connections shall not be used
						in areas other than outdoors.
2-3.6 Underground piping shall be installed on a bedding
						of at least 6 inches (15.24 centimeters) of well-compacted backfill
						material.
2-3.7 In areas subject to vehicle traffic, the pipe
						trench shall be of sufficient depth to permit a cover of not less than 18
						inches (45.72 centimeters) of well compacted backfill material and
						pavement.
Exception 1: In paved areas where a minimum of 8 inches
						(20.32 centimeters) of asphalt paving is used, the depth of the backfill
						between the topmost tier of piping and the paving may be reduced to not less
						than 8 inches (20.32 centimeters).
Exception 2: In paved areas where a minimum of 6 inches
						(15.24 centimeters) of reinforced concrete paving is used, the depth of
						backfill between the topmost tier of the piping and the paving may be reduced
						to not less than 4 inches (10.16 centimeters).
2-3.8 In areas not subject to vehicle traffic, the pipe
						trench shall be of sufficient depth to permit 6 inches (15.24 centimeters) each
						of bedding and cover of well-compacted backfill material. A greater burial
						depth shall be provided when required by the manufacturer's
						instructions.
2-3.9 Piping within the same trench shall be separated by
						more than 3 times the diameter of the larger adjacent pipe.
2-3.10 Piping to equipment shall be provided with an
						accessible, manual shutoff valve.
2-3.11 Pipe, tubing, fittings, and other piping
						components shall be capable of withstanding a hydrostatic test of at least 3
						times the rated service pressure without structural failure as documented by
						the manufacturer.
2-3.12 All natural gas piping shall be installed in
						accordance with R 29.4601 et seq.
2-3.13 All liquefied petroleum gas piping shall be
						installed in accordance with R 29.4001 et seq.