Thanks for the info. Time for a trip to the plumbers merchant.
:)
One further quick question.
Should the check valve be fitted vertical or does it not matter?
I am not very experienced with plumbing, but want to fit a replacement monoblock tap to my kitchen sink.
In the fitting instructions of the new tap there is a note which says 'if this product is being fitted to a water system with low pressure hot water feed and high pressure cold water...