options on large 1 pipe steam balancing

Chas_2

Still having a few promblems on a large 1 pipe system mainly getting steam to the farest main,i have done just about all i can think of including removing all main vents off of the other 7 mains and still this main is slow and even with the other vents plugged there basically no difference in the amount of time it takes for steam to reach that end of the main vent ,I have a hunch that this main heats slow is due to the near boiler pipng and the existing velocity of the steam from the boiler my math using some of dan's formula in the LAOS and i come up with 37.5 fps as the boiler exiting velocity,now as for all my steam boilers i install i fiqure my header size by doing the math to fiqure out the exiting velocity and i usually pipe and size my header for a velocity of 10 to 15 fps and i have yet to have any issues of slow mains and such .I have a few more tests to perform but am i wrong on my hunch that this main the farest from the boiler could be suffering from slow wet steam and that be the cause for all the promblems as to why this main takes forever and the rest of the building is boiling .I have had the landlord finally fess up to not replacing rad vents which i had his workers do all 96 rad vents and they are all gortons ,basically 4 and 5 and on the promblem apartments they insalled 5 and 6 and 3 gorton #1 on the end of the main,No one has really given me a answer on the near boiler piping either as burmham states the header is fine but at 37.5 fps i am not buying it ,could high boiler exiting velocity really play that much into even heat distrubtion because of the wet steam the boilers producing .I have skimmed this boiler and it's clean from the first temp reading i had taken off the header where only about 185 now after many skimming section i have the boilers header temp of a little over 200 which is a improvement ,Thanks for any insight that you may come up with as for me i would have never piped the near boiler piping the way it was done but thge landlord does not want to pay big bucks for the proper near boiler piping i think i may be getting to my wits end thanks again peace and good luck and happy and safe holidays clammy

Chas_2

bump

I guess no one has any info wow that's a first all brains stumped no input no ideas wow is it that i'm the only one who looks at exiting velocity i guess so the pro who installed it did not clammy

Steamhead (in transit)

Check that main with a fine-tooth comb

Something in that main is holding back the steam. I'm sure it worked fine when originally installed- what has changed in that time? Is there any banging or boiling noises in the main?



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Chas_2

no banging no boiling

frank this part is really stumping me ,there is no start up ,mid or end of the cycle banging or hammering noises .this is the quitest i have heard this systems piping ,i would fiqure that if there was a blockage that the main would hold back condensate which would cause some minor hammering but none ,the vent at the end of the main just pants slowly and way before the pipes are even getting hot there's a slug of hot condensate running down the bottom of the pipe at least5 minutes before the pipes start getting hot ,Am i on the right track thinking that all the latent heat in the steam is jumping ship just to supply the enough heat for the pipings pick up factor and then after that it on to the rads .i know from other smaller bolers i have piped that the boiler rooms or standing near the boiler's near boiler piping you are usually sweating you but off, but here with this boiler the boiler piping just ain't cooking even after about 5 or 6 skimming sections and the sight glass is clean very mimiun surging if any it just does not seem that the piping is really cooking plus i would think that a back pitched 3' main to the header is not helping dry things out either.I'll talk to the building owner again and see if he's willing to pay and cut open one or two spots in the troubled main and look for blockages but i have already flushed it out twice and also clean drip lega i had installed on the loop seal ,the first cleaning reavieled alot of crude but i just re checked them on thusday and they where spotless no rust,mud or sediment present ,thanks for any other ideas ,what's your thoughts on the exiting velocity and it's possible effects on low latent heat carring steam ?peace and good luck clammy

scrook_2

Are all the mains (especially the long one & including fittings) WELL insulated?

Is the boiler possibly marginally sized for the connected load (including the long main and it's pickup factor)?

If you temporarily block the main vents on the shorter main(s) can you get the long one to heat faster/better?

scrook_2

Are all the mains (especially the long one & including fittings) WELL insulated?

Is the boiler possibly marginally sized for the connected load (including the long main and it's pickup factor)?

If you temporarily block the main vents on the shorter main(s) can you get the long one to heat faster/better?

Steamhead (in transit)

That \"heavy breathing\" from the vent

means there's water standing in there someplace. The system is now running well enough that it doesn't bang, but it's still slowing the steam.

Check your e-mail.

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V8toilet

Did you try removing the main vent completely from the slow to heat main and see if the steam gets there quicker. Is the main the right size pipe for the connected load? Is the boiler under fired? Try closing off some radiators to reduce the connected load to see if that helps. If it does you may have to re pipe.

When the installer first installed my boiler he used 2" pipe that was too small for the header and riser and the exit velocity was around what yours is. I made him reinstall 3" pipe in it's place to bring the exit velocities down to 15 fps and the radiators heated more evenly and more quickly too so it does makes a difference for sure.