On Sun, 16 May 2010 19:23:20 +0100 (BST), "Dave Liquorice"
wrote:

There are two restrictors supplied with a new valve, a HP (lots of
fins IIRC) and and LP (not so many fins) but you can use a torbeck
without a restrictor if your supply is gravity from a tank on the
floor above say.

Thanks. What are the definitions of high and low pressure? Is mains
always considered high pressure and gravity-fed is low pressure or
isn't it as simple as that? Our pressure should be 3 bars; there is a
prv to stop it going higher than that. Would the pressure on the first
floor be lower than that due to it having to fit gravity to get there?

This is the factory fitted valve, and I don't remember seeing any
spare parts or instructions or if there were, I expect they are long
gone. I shall see if I can remove whatever is in situ, otherwise I
guess I'll have to buy a new valve to ensure I get all the parts.

Thanks again.