CSA ANSI LNG 4.1:2018 pdf download.Liquefied natural gas (LNG) dispensing systems for natural gas vehicles (NGV)
1.1.1 This Standard applies to:
a) the mechanical and electrical features of newly manufactured stationary and mobile systems that dispense“cold" or "warm”liquefied natural gas for vehicles where such a system is intended primarily to dispense the fuel directly into the fuel storage container of the vehicle;
b) LNG dispensers contained in a single housing; and
c) LNG dispensers contained in multiple housings for metering and registering devices, remote electronics, overfill protection, hoses, and fuelling nozzles.
1.1.2 Each dispenser may have the capability of independently fuelling more than one vehicle simultaneously.
1.1.3 Dispensers covered by this Standard are intended for use with liquefied natural gas, a fluid in the liquid state at cryogenic temperatures that is composed predominantly of methane and that can contain minor quantities of ethane, propane, nitrogen, or other components normally found in natural gas.
1.1.4 This Standard does not apply to:
a) rail locomotive dispensing systems;
b) marine vessel bunkering systems;
c) compressed natural gas dispensers;
d) fuel management systems or point of sales systems; and
e) remote sequencing equipment and other remote equipment not supplied as part of the dispenser.
1.1.5 Installation of an LNG dispenser is intended to be in accordance with NFPA 52, or CSA B108, Part 2, as applicable, and the requirements of the authority having jurisdiction (AHJ).
1.1.6 In this Standard,“shall" is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard;“should" is used to express a recommendation or that which is advised but not required; and "may" is used to express an option or that which is permissible within the limits of the Standard.
5.6 A dispenser shall have provisions for operation in conjunction with an Emergency Shutdown Device (ESD). Activation of the ESD shall cause the dispenser to disable the flow of LNG to the vehicle fuelling hose, shall shut off the electrical supply to the dispenser (see Clause 7.6), and remove the LNG supply to the dispenser.
5.7 In the event of a loss of electrical power, the flow of LNG to the fuelling connection shall be shut off automatically, and the dispenser shall shut down in a safe manner. A manual operation shall be required for the dispenser to resume operation.
A power interruption shall automatically close the safety shut-off valve and automatically open valves to capture boil-off gas.CSA ANSI LNG 4.1 pdf download.