Delphi-Common Rail System – Excess pressure safety valve
1 High-pressure connection
2 High-pressure channel
3 Ball valve
4 Valve spring
Inside the high-pressure pump, just in front of the high-pressure connection is an excess pressure safety valve incorporated into the high-pressure channel.
If there is a malfunction in the system, this is an additional safety feature to prevent the fuel pressure from getting too high.
If a specific maximum permissible fuel pressure is exceeded, the valve opens against spring force and the fuel can escape into the high-pressure pump’s inner chamber.