CSA ANSI IAS NGV 4.2-1999 pdf download HOSES FOR NATURAL GAS VEHICLES AND DISPENSING SYSTEMS
1.3 GENERAL CONSTRUCTION
1.3.1 The construction of hose parts not specifically 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 construction as will provide at least equivalent performance.
1.3.2 The nominal hose diameter shall refer to the finished internal diameter ± 0.65 mm (0.025 in) for sizes up to and including 20 mm ( 3 / 4 in) and ± 1.25 mm (0.05 in) for sizes over 20 mm ( 3 / 4 in). A tapered plug gauge having a taper of 30 mm/m ( 3 / 8 in/ft) marked to indicate variation of 0.5 mm ( 1 / 64 in) in diameter or other equivalent means may be used for measuring inside diameter.
1.3.3 The inner tube surface and outer cover shall be smooth, of uniform thickness and free from imperfections. The intent of this requirement is not to exclude the use of a corrugated or perforated cover.
1.3.4 The outer cover shall be constructed to minimize or prevent fluid penetration into the inner plies, braids or tube. The inner plies, braids or tube shall be resistant to the effects of common automotive fluids, as determined by the method of test in 2.20 FLUIDS EXPOSURE TEST.
1.3.5 A hose for high pressure service shall be constructed in such a manner that permeation or leakage from the inner tube does not expand or damage the outer cover, braids or inner plies. The manufacturer shall provide evidence of compliance with this provision, as tested in accordance with 2.21 VERIFICATION OF HOSE COVER PERFORATIONS.
1.3.6 Dispenser hoses shall be suitable for use at a temperature range of -40°C (-40°F) to 65°C (150°F). Hoses for use in vehicle engine compartments shall be suitable for use at a temperature range of -40°C (-40°F) to 120°C (250°F). Hoses for use on vehicles outside the engine compartment shall be suitable for use at a temperature of -40°C (-40°F) to 93°C (200°F).
1.3.7 Hose assemblies shall be constructed so as to provide an electrically conductive path between couplings at each end of the hose in order to dissipate static electricity. (See 2.5 ELECTRICAL CONDUCTIVITY.)
1.3.8 Dispenser hose outer covers shall be constructed of non-electrically conductive materials (i.e. metallic braids will not be exposed between ferrules).