Answer: The filling nozzle is a complex device whose function is defined by international technical standards. Compliance with these standards must be confirmed by quality certificates. The design of this component was focused on user comfort and protection.
The filling hose nozzle is inserted into the filler neck on the vehicle and is fixed in this position by turning the lever on the injector handle. In this case, there is an analogy with the systems for refueling vehicles with LNG, which have been used throughout the planet for many years.
In addition, the automatic sequence of the refueling process – first of all, includes checking the tightness of the connection of the refueling hose to the vehicle tank. For this purpose, the residual hydrogen pressure in the vehicle tank and in the refueling hose is used. When the hose is connected to the vehicle tank, the pressure is measured over a period of time. The next filling phase can only begin after confirming that there is no pressure drop in the system. If a pressure drop is detected, the control system stops the process and reports an error: leaking hose connection. A similar error can also occur if the O-rings on the filling nozzle have been damaged or dirt has got into the joint. The connection will also be leaky if the filling nozzle is connected to the wrong counterpart. This malfunction can be easily eliminated by the station technician.