CSA  NGV 4.1-2018 Natural gas vehicle (NGV) dispensing systems.
Type 2 — a nozzle for use with a dispensing hose that remains fully pressurized at dispenser shutdown. A three-way valve connected to the inlet of the nozzle is required to safely vent trapped gas prior to nozzle disconnection. With a Type 2 nozzle, the vent valve operating mechanism is external to the nozzle.
Type 3 — a nozzle for use with a dispensing hose that automatically depressurizes [517 kPa (75 psi) and below] at dispenser shutdown.
Class A — this class specifies high frequency use, with a cycle life of 100,000 cycles. Class B — this class specifies low frequency use, with a cycle life of 20,000 cycles.
Pressure — expressed as psi, kPa, or bar.
High pressure — in the NGV context, 4 bar (60 psi) or greater.
Service pressure — the settled pressure at a uniform gas temperature of 21 °C (70°F) when the
vehicle fuel container is fully charged with gas. This Standard defines standard pressure of
101.325 kPa (14.696 psi) at 288.15 K (15.00 °C, 59.00°F). This pressure may be 2400, 3000, or
3600 psi. Alternatively, pressure may be 200 bar or 240 bar at a uniform gas temperature of 15 °C.
Test pressure — the pressure to which a component or equipment is taken during testing.
Pressure relief device (PRD) — a one-time use device, triggered by excessive temperature and/or pressure, which vents gas to protect the cylinder from rupture.
Pressure relief valve — a device that prevents a pre-determined upstream pressure from being exceeded.
Purge — to replace the existing fluid (gaseous or liquid) in piping, tubing, equipment, or a container, with a desired fluid.
Rated discharge conditions — rated discharge pressure and temperature are the highest required to meet the conditions specified by the purchaser for the intended service.
Service temperature range — the temperature range the cylinders will be subjected to in normal service.
Station — Fast fill station — a fueling station where an individual vehicle fill flow-rate is greater than
200 SCFM.
Fueling station — a facility for the dispensing of natural gas and includes all stationary equipment
and associated components downstream from the inlet of a compressor manual shut-off valve. Valve — a device by which the flow of a fluid may be started, stopped, or regulated, by a movable part that opens or obstructs passage.
Automatic — a self-actuated or remotely actuated device consisting essentially of a valve and actuator.
CSA  NGV 4.1 pdf download.