such choice - is it just personal preference or are some types more suited
than others for certain applications? I have always liked ball valves for
their ease and speed of operation, but I need to add/replace some valves and
wondered if ball is the way to go here (all 15mm copper pipe)

* Cold feed to boiler (& washing machine) and hot water from boiler to rest
of house
* Isolation for outside bib tap
* Sink taps (I assume small "service" valves with a screw rather than a
handle - these are small ball valves too arent they?)


Also, does a 15mm end feed elbow add significant restriction to the flow as
opposed to a 90deg bent pipe (bearing in mind there is ~10 l/min restriction
on the flow anyway in the combi boiler)? I could always reuse the existing
bend after cleaning it up but I have no means of bending new pipe at the
moment.


cheers

Dave.