The CNG Zafira has one safety valve for each pressure vessel.
The safety valve has a plurality of functions and enables the pressure vessel to be filled from one side through a non-return valve.
The non-return valve is located in the neck (2) of the pressure vessel after the safety valve has been installed. This prevents gas from flowing back into the filler duct.
Another task is to open the gas supply through the electromagnetic valve (5). This takes place after switching on the ignition and with a minimum engine speed of 820 rpm.
This is comparable to switching on the petrol pump in an petrol engine. Closing the electromagnetic valve after switching off the ignition prevents gas loss from the pressure vessels.
This function provides greater vehicle safety in two regards: Firstly, no CNG can subsequently flow through any of the lines, secondly, no CNG can subsequently flow through the engine.
The safety valve has a melting fuse (1) which opens, for example, in the event of a vehicle fire, and permits controlled venting of the CNG. This destroys the melting fuse.
With repair measures, the safety valves on the pressure vessels can be made safe by closing the manual lock (3).
The gas delivery line to the pressure reducing valve is connected using a bolted connection to the threaded connection with integrated non-return valve (4).
| 1 | Melting fuse | 4 | Threaded connection port for gas delivery line with integrated non-return valve |
|---|---|---|---|
| 2 | Non-return valve (in neck of vessel) | 5 | Electromagnetic valve |
| 3 | Manual cutoff valve | 6 | Connection line between the pressure vessels / tank modules |
ПримечаниеDriving the Zafira Z 16 YNG into parking and underground garages is permitted through the installation of the safety valve!