How far should the disk be open on a Radiator steam valve??

Pete Novak

I just bought a replacement angled steam valve for a one pipe steam system radiator. (1 1/4in pipe) When the valve is opened all the way, the bottom of the disk just sits at a position that is slightly more than half of the diameter of the inside of the pipe. So if you're looking into the valve from the radiator side, the disk only looks just over half way open. Is this correct for this type of valve? Being new to this sort of system, I would think that disk should sit near the top of the pipe, not just over half way. Was the valve that I bought defective, or do they all look like that?? Thanks!

Steamhead

I see that a lot

but so far I haven't had trouble with one.

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Pete Novak

Have you seen any that were fully open, and

if so, why would't you use one of those? Doesn't that opening affect steam velocity?

Steamhead

Only on the old ones

all the newer ones I've seen lately opened 1/2-2/3 of the way. But when I've put them in they've worked. You'd think it would affect the velocity- but look at the size of the air vent. Steam can't get in any faster than that.

Sure, I'd prefer a fully-opening valve- but what are you gonna do if you can't get one?

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