which pipe is return and feed?

[bmw9818]

just done an m20 swap im hoping to start it in one go and not go back in as i so cba and my backs hurting!

there are three pipes ones a breather,

other two are together could someone poss tell me which one is the feed or return line? bottom ot top one

also the feed connects directly at the injector rail right and reg is return?

thanks

[maxfield]

Reg is return yes and feed is directly to rail.

Put both pipes into a container and turn ignition on see which squirts fuel.

[e30topless]

the top pipe is the feed