Hi Folks,

I'll measure the outside of the barbs in the morning, when I can drag myself out to the workshop. I did try a bit of 4mm PUN tubing (that is just the Festo designation, or part number for the tubing by the way, I think it stands for Polyurethane), and that seems to fit on nicely. 3mm is going to be a really big stretch, although I will try heating it up (thanks for the tip!)

Turbinepeter, do your valves have the push in fittings, or the black plastic base with barbed fittings? Also, whereabouts in Cheshire are you based? I used to live in Northwich, but have since moved to North Wales

Cheers
Andy