jJim McLaughlin wrote in
:

I'm replacing a toilet supply line valve.

Toilet is on lowest level of house, and supply line valve is
literally the lowest valve in the house and supply line is
literally the lowest water line in the house.

I plan to turn off the main shut off, and open cold water valves up on
third floor (the upper level) and the cold water valve in that same
lowest level bathroom's sink.

Then I plan to open the toilet supply line valve and drain that line
into a low flat pan before removing and replacing the old valve.

Is there anything obvious (or maybe more importantly, not so obvious)
that I'm missing regarding draining that line?

I *think* I've got the drainage issues / air issues / vacuum issues
covered,
but I'd rather avoid draining 10 gallons of water into a pan that
holds maybe 2 gallons.

I'll have the wet dry shop vac and a bunch of towels handy in any
event.

Thanks for your comments.


I'll have the wet dry shop vac and a bunch of towels handy in any
event.

No plumbing wizard but I would think, assuming the valve somewhat works,
you can use the valve to stop the draining so you can empty pans, wring
out towels, call 911, etc.