Inadequate Pitch

Jim_97

I have a one pipe steam system with two mains, both completely insulated. It's a parrallel flow system with a wet return -- steam and condensate flow in the same direction to the end of the headers, where they're dripped to a wet return.

I've been having a problem getting the two radiators at the end of the shorter main to heat. I've noticed steam is much *quicker* to reach the end of the longer main than the shorter one. I've experimented with main venting (going from a Gorton #2 at the end of both to a Gorton # 2 at the end of the short main, with the long one capped -- no change. I've even tried throttling back on all the radiators on the long main, changing air vents to the slowest venting Gorton #4s. Still no change. Steam always reaches the end of the longer main first, and then within 5 minutes begins to heat the rads connected there. Meanwhile, it takes the steam an extra 5 - 10 minutes to reach the end of the shorter main, and an extra 15 - 20 minutes to begin to heat the two rads connected there.

The long main extends 43'6" from the boiler header.
The short main extends 35'6"

Both are piped with 2" cast iron.

I've never heard any banging, knocking, or seen any air vents spitting water.

BUT -- after reading Dan's "Lost Art of Steam Heating", I thoguht to check the pitch of the steam mains, and there is a significant difference.

The long one is pitched downward 4" over it's entire course. The short one is pitched downward only 1.25" over it's entire course.

Is there any way to rectify this problem, without doing a complete repipe of the short main?

Thanks in advance for the help

gerry gill

which main

is the first to recieve steam from the header?

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Jim_97

The long main

receives heat first -- it's ahead of the shorter mean both closer to the boiler, and all the way to end of the main.

Also, the Gorton #2 at the end of the short main tends to "pant" -- kind of breathes in almost as much as it's breathing out. This, even though all the pipes are well insulated.

Jim_97

Sugestions

... anyone?

Steamhead (in transit)

You definitely have water trapped in there

you might try loosening the pipe hangers at the end of the main and lowering it a bit.

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Jim_97

Thanks, Steamhead.

I was thinking that should be my next move. If I loosen the hanger at the end, and it barely moves, how inadvisable would it be to do a pull-up or two, so it budges downward?

I wouldn't be too happy to snap the end off the main, but will go to quite some length to avoid a complete repipe!

Thks again