I have a circuit diagram for a power supply which calls for 2 x 16 mfd 350v wkg. capacitors. Can I use a dual 16ufd capacitor rated at 450v instead. Thanks.

Yes, assuming two things. The negative of both caps goes to the same point so as to allow a dual unit. Also, that the dual unit is not a 50 year old dual aluminum foil electrolytic which may give up on you after voltage is applied (as in short... kaboom).

Curtis Eickerman

I can second the suggestion to not use NOS capacitors from "back when".

I had a few NOS Sprague metal can caps still in the box. Installed one as a trial on a small radio. It played for about 30 seconds then POOF!!

Forget about 'reforming" (if you have heard about that) a capacitor. It may work for a while but you're still dealing with an old cap. It is cheap insurance to use a
part. Foolish and false economy to save a few cents using an old part.
Good luck with your project!

+1 Old caps have a way of taking down other components as well. If a transformer is involved which could take big bucks to replace, you will never use old stock stuff again.

Thank you all for your answers. The capacitor in brand new and both negatives go to the same point. Once again, thank you & kind regards.

In alot of instance there is a date code on the thing-although it may be cryptic

What I generally see are two digits for the year and two digits for the week in the year

If in any doubt toss it and get two 47 MF 460 volters current production. Old parts are prone to failure exen if never used.