Vacuum switch - Water valve

Could any one tell me where the vacuum pipe on the Water valve switch should go to? It's the one arrowed in the pic. It's on a 95 Disco 3.9 V8Efi
If it goes in the back of the plenum where does the fuel pressure regulator vacuum pipe go?

I wish I could find a definitive diagram of all the vacuum pipes on the V8, it would solve a lot of my problems.

I've put this in the Disco section aswell, hoping for a speedy answer.

Problem solved. It shouldn't be there, a previous owner must have added it with the LPG conversion, it is coming out.

id agree

it was a factory fitted part though not sure why?