On Wed, 8 Jul 2020 at 18:01, Rupert Boleyn <
xxxxxx@gmail.com> wrote on expansion tanks:
It's a sealed tank that has both air and water in it (separated in a
modern tank) that's there to smooth out pressure spikes from water
hammer and to stop thermal expansion doing terrible things to the
plumbing. Wikipedia has a more complete description, FWIW.
Doh! See how old school I am, I never even thought to try wikipedia. (For 'old school' just read: old).
But thank you. I now (sort of) know more than I ever wanted to on the subject. I'll leave it in. It balances that side nicely. :-)
tc