Non return valve on fuel pump

Hello all,

Been having starting issues with my vrs, I have been told to try a non return vavle on the fuel pump pipe as there could be a fault thats letting fuel back when its been left standing for a while... and this is alot cheaper than replacing the pump.

I have the part but i can't remember what tube to fit it or what direction it should go anyhelp would be great thanks

below is where i was told to fit it just dont know what pipe, on closest the back or front of engine bay