In message , at 11:46:26 on Fri, 30 Oct
2020, thescullster remarked:
Roland Perry Wrote in message:

Struggling to find the keywords to guide me to buy online those
plumbing gadgets which clamp on the outside of, and pierce through,
existing pipework to attach a dishwasher feed or something similar.--
Roland Perry

If you are fitting a drain valve to empty the whole system, then
this should be one that allows good flow.
That way there's a chance the water velocity will carry crud with it .
The "pipe cutter" types will not do this for you.

I'm using the pipe-cutter valve to empty the system, so that I can put a
more conventional bleed-valve elsewhere.
--
Roland Perry