Some long awaited feedback. I tested various "bicycle" valves and all have failed. I did many modifications to the valves to try and stop the constant dripping. I have now given up on what I thought was a good idea as a lost cause.
However there is a light at the end of the tunnel. I found a supplier of water nipples.
Those are the types they supply. the cost of this is R8.17 (not sure about the VAT).
Spartan Poultry Equipment Head Office
62 Summit Road
Blue Hills
Halfwayhouse
Midrand
Office Number +27 11 318 2239
Spartan Pietermaritzburg
Office Number (033) 387 6233
Spartan Cape Town
Tel Number (011) 318 2239
I really hope this helps you all. I am going to get myself a few to test them out once they reopen in 2012. I will then post a full report and pictures on the system.