In message , IMM
writes

Plumbing Mechanical Service Book 2, a NVQ plumbing book. This is not a DIY
book so please don't buy. It has a section on heating, and a sub section on
Mini-bore on page 170. It says:

"If the manifolds can be situated in such a way that the branch flow and
return to each radiator is approximately the same length, the frictional
resistance will also be approx the same, making the system self balancing".

And on page 171:

"In a well-designed system balancing should not be necessary as the aim is
to keep all pipe runs to heat emitters at, or near, as possible, the same
lengths."

And on page 172, there is a cut-away of a twin entry rad valve without
lockshield adjustment because in properly designed mini-bore systems, which
is easy to do, balancing is not required.


And I thought that NVQ was for people too thick to take "O" levels

--
geoff