Mike Halmarack wrote:
On Wed, 11 Sep 2019 09:28:59 +0100, Chris Green wrote:

Mike Halmarack wrote:
In my fumbling enthusiasm to get out from under the kitchen sink, I
overdid the leverage and broke the spindle of a seized gate valve. So
now it can be turned forever in any direction with no effect.

Will I have to replace the whole thing, or can I remove the guts from
the main body of the valve and renew just those inner parts?

It's probably easiest to replace the whole thing except the nuts
and olives. I've replaced a couple with full-flow lever type valves
which have fitted the same nuts and olives OK. If you replace with
same/similar gate valves then remember to turn back half a turn or so
from fully on or fully off, though I'd recommend lever type valves
instead really.
I think you're right, replacing the whole thing with a lever valve
would be best.

It's just that I'm concerned about being able to temporarily increase
the gap between the pipe ends to let the new valve in, without
unwanted knock-on effects.

It is most unusual for pipe work to be that €˜tight you cant wiggle it
enough to get a gate valve or other fitting out to swap it.

Id measure the one there and try to find a near replacement- most are
around the same size. While, in theory, you should replace olives, they can
generally be reused if you clean then- I use a nylon pan scrub. Check they
arent damaged etc.

A tip for next time. If a tap or gate valve is seized, undo the gland nut a
fraction of a turn then try it. It generally works. Dont forget to
retighten.