"Mungo" wrote in message
ups.com...
Obliged for the reply Jeff. I took a look at the RS website but I got
bamboozled
by whats on offer.
I guess there isn't one fitting that will fulfil my needs - perhaps a
combination
of a couple of fittings?

as Andy has rightly pointed out, air pipe is 4mm, 6mm .... it sounds like
you have the sort of pipe used in aquarium applications, if b&q don't do the
fittings then try an aquatic shop

Regards Jeff