If radiators are removed and capped - Will you steam still go up riser?

Steamer30

I maintain a building where someone came along some time ago and did the usual with those who don't understand steam and they removed radiators throughout the building and capped off the supply and return pipes. Will steam still come up the riser and create hammer if they are capped or should I be looking elsewhere for the hammer?

Abracadabra

Steamer30 said:

I maintain a building where someone came along some time ago and did the usual with those who don't understand steam and they removed radiators throughout the building and capped off the supply and return pipes. Will steam still come up the riser and create hammer if they are capped or should I be looking elsewhere for the hammer?

Steam should not be coming up the riser if all radiators on the riser have been removed and everything is capped.

Steamer30

What is on the first and third floor they were removed but the radiator was kept on the second. Would that cause water hammer??

Fred

If this is a 1 pipe system, Check the horizontal from that riser to the radiator. If that does not have proper pitch, it will cause hammer. If it is between the floor and the 1st floor ceiling, if you can raise the entire radiator up a 1/2" or so and then repitch the radiator, towards the inlet side, that should give you enough pitch in the horizontal supply to drain condensate.
If it's a 2 pipe system, make sure the radiator is pitched towards the outlet side of the radiator.

Steamer30

It is a two pipe system. Thanks for the quick response. I have checked that radiator - it is pitched correctly, has a rebuilt trap and a new radiator valve as well (one one the second floor). Just was curious if the riser as it goes to capped off one on second floor could trap condensate from steam going up to the second floor radiator. Then when steam comes up next cycle - could it be making the hammer. Ive checked and replaced all traps and main line F&T trap was replaced in December. Just trying to locate source of this water hammer.
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Fred

Beyond the second floor, that riser should be filled with air and should not let steam up there, assuming the caps on any of the capped run-outs aren't lose or leaking and letting the air out enough to let steam into the horizontal that fed those rads.
Edited to say: "any of the capped run-outs"

Steamer30

Thanks - Ill make sure to check capped off ones are secure and not leaking air out that would draw steam. I should have thought of that.