On Thu, 10 Sep 2009 21:46:56 +0100 (BST), "Dave Liquorice"
wrote:

What has been there for a while now is a lever operated
15mm 1/4 turn valve.

Easy to use, quick on/off, good flow rate (which could be improved by
using a full bore valve but isn't necessary. IIRC it's a normal 15mm
tank connector, short bit of tube, valve, then a bit of tube with an
elbow to direct the flow down. I think 22mm would be a bit too fast.

Thanks. That is interesting. I thought 15mm plumbing might be too slow
because I had read threads here about the flow from the tap being so
poor. I realise now I must have made a mistake: these posts must have
been about the supplied taps rather than 15mm bib taps. (What is a bib
BTW?)

Quoting back-to-front:
I tried a bib type tap but the plastic of our butt is to wibbly
really and you have to turn it full on (turn turn turn...) to get a
decent flow.

Is there a way to reinforce the butt. Since it would be submerged, I
guess it would have to be brass. Could a brass plate be put inside
behind the tap? Where could you buy a suitable square of brass from?