Roger Mills wrote in
:

On 20/03/2018 17:51, DerbyBorn wrote:
In my loft I found a bit of a leak.

The hot and cold to the shower both have a in-line stop tap and then
a non- return valve / check valve. (30+ years old)

The stop tap is weeping a bit and other parts are a bit crusty - I
think I should make up a couple of new lengths with new valves (for
what they cost) and splice it into the existing pipework.

Any recommendations on what fittings are best for this job - bearing
in mind it is hidden away in the loft?

What size pipe? Metric or Imperial? What material - copper or
stainless steel?

Assuming it's copper pipe in metric sizes, use solder joints when
splicing new sections in. Once you have checked they don't leak, you
can forget about them.

When replacing the stop taps, use full bore lever-operated ball valves
instead of bib taps.

In a later post, you ask whether check valves are essential. Where
does the water come from for the shower - is it gravity flow from a
header tank for cold and a vented stored hot water system - or is it
all at mains pressure, with an unvented hot water system or combi
boiler? You only need double check valves if there's a danger that
dirty water could get sucked into the mains in the event of a mains
failure.

Was thinking the valves would be at each end of a new bit of pipe.