I have four pipes connected to my valve - two that run parallel with each other from the front end of the chassis to the valve and two that disappear upwards into the area of the spheres. In both cases one of these is the flow and the other the return.
If you call into your local dealer and ask them to call up the pipe configuration off the CD-ROM, they will show you on screen how the pipes fit - they may even print off the exploded diagram (Merecedes Benz UK at Milton Keynes usually do).
1987 230TE (W124/M102) RH Drive 4-speed auto, 7 seater.
Some days you are the bug; some days you are the windshield