counterflow steam ????

Mellow_2

We change this system from an old coal boiler, that cracked. I normaly would run one two inch drop header and tee the two lines off the top(it could have been done this way) but this system is a counter flow and should be fead steam into the top of the mains. It has two mains and only 320 sq. ft. of steam needed....... The system ran half the winter with no STEAM problems. My question is should both ports on the supply off the boiler be used this way? I think two 2" pipes will move the steam better than one but on this small of a boiler the reps. only want me to use one supply port. I was told the larger the pipes the better and running the pipes this way should double the pipe size. we fixed the mains and added new main vents........and balanced the system. what do you think?

Unknown

Had an almost identical install a few months ago

A dry fired Peerless on a counterflow system . We built the near boiler header like we always do , with a drop . We also incresed the size to 2 1/2 inch . From the near boiler main we connected to the 2 separate system mains by dropping into them with 2 inch 45s . We added 2 new returns that drop to the floor also . The job has been steaming great since October .

Like Ken said , very nice install Mellow .

Ken_8

Beautiful job and

nice idea with the dropped header piping IMHO. Although I generally suggest on small (under 500 SF of EDR) systems a drop header is a solution to a problem that doesn't or shouldn't exist, in this case it is a helpful design!

Nonetheless, I would have prevented what you may have induced: namely, an imbalance within the boiler steam chest. Rather than have the resistence of the two independent mains (and EDR attached thereto) decide which boiler riser would have less or more steam flow (perhaps causing water throw on the least restrictive riser), I would have joined them into a single header with two take-offs. By doing so, branch and equalizer differentials would be a moot point as far as the riser/steam chest dynamics are concerned.

I suspect the system runs as well as you suggest because the EDR, friction and returning condensate are somewhat balanced. If so, you lucked out.

Funny, steam can be like that :-)

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EBEBRATT-Ed

Nice Job! But I agree with Ken. If I'm looking at the pictures correctly you are using the 2 boiler supply tappings to feed each supply seperatly. This is probably the way the coal boiler was. Your using the boiler itself as a header and the new small boilers are not made for that. But by using both tappings--it will get buy. Read Dan's book the "lost art".

Don't take my comments the wrong way--you did a beautiful job and obviously take pride in you work. And I'm sure you will have no problem with it.

But some jobs wouldn't work if piped that way

clammy

i agree

I agree but like ken says steam can be strange .I,ve ran into and replaced a few counter flow systems and usually i take the same approach as most steam jobs i would have made a header tying my supplies together piped my 2 supply take offs and drop for my equilizer and of course incresed my pipe size to 2 1/2 and feed into the top of the existing header with a tee and piped a full size drip .Other wise it looks great it always alot of work and there's always in your mind what you could have done different or better .I've also found that some times when you vent the ends of the mains on a counter flow that you may have balancing promblems between the main s even when there pretty much the same size lenght and load i do believe it has to do with where you tie off of your boiler header but when removed and plugged the systems heated a little slower but much more even then with the main vents but ever job is different it's always great to view some steel pipe installed properly peace clammy

Ken_8

Also,

Wassupwitdat coil plate CxM take-off?

Looks like a HWBB zone supply or return?

I'm curious as to why you didn't use the preferred tankless coil for a sub system for HWBB - if in fact that was your intention.

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Mellow_2

thanks for the info

If the system was biger I would have done things differant...... but the load on this boiler is small. maybe 150 sq. ft. of radiation on each two inch line. The steam should be moving very slow and dry. the vent on the larger line is a #77 and the small line is a #35. I only have an indirect on this boiler no BB so we wanted to get the best recovery for the indirect..........We taped the coil plate so we can get a 1" supply to the indirects and have the supply and return on diagonals.........(we have changed the piping here from 3/4 to 1" not shown here)............ I wonder what would be a problem you could have with this steam system...... with the pipes like this....... two 2" supply pipes not tied together ......... With one 2" supply the steam should be moving faster right? The water should not be pulled out of the boiler even if it is drawing uneven or why would it????? thanks again

Al Gregory

Nice looking job. Do u prefer the old 6 LWC over the probe types. I hate them and do away with them any chance I get. Also around here that wouldnt pass inspection cause the gas water heater is vented below the boilers smoke pipe.

Mellow_2

Al

I have used both types and have found good and bad things with them both........ Thanks for the info on the gas WH, it was already there and that is not, the only bad thing in the basement. (had to take a very small pic, just want to show my work) thanks again

Scott Kneeland

If I'm looking at it correctly it looks like a Peerless EC03?. If so you only need to use one supply tapping as per Peerless install manual. I also don't see a equalizer. I have gotten away from drop headers on small counter flow boilers by adding drip legs.

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EBEBRATT-Ed

I think because you have and used the "extra" 2" tapping and slowed the steam down you will have no problem. But on a larger boiler(more sections) piped this way you could have trouble with uneven water line (if one side had more load).

You can't do everything perfict all the time. It's ok to cheat occasionally. Just gotta know what jobs to do it on.
Ed

Mellow_2

brainteaser.............

dan sayed the counterflow was normaly "very small systems" with that in mind...............the system can only be small and with a small load.........as long as the mains are about the same size the load should never be more than the 2" tapps could handle, right???? I know this is not Ideal for balance but ...............I have to ask. If the load was more than two 2" pipes of steam it might not be counterflow. Maybe?

EBEBRATT-Ed

I don't feel counterflow is the issue.We don't need to beat this to death.You slowed the velocity of steam leaving the boiler by using both tappings so it should be ok.But it is always best to header the connections in a steam header rather than using the boiler as the header. The small boilers are not made for that. The old coal boilers had large spaced for steam diingagement.

Mellow_2

Ed

not trying to beat it to death just trying to learn. thanks for the help and you have a good point. The only real question I had was to compare the two ways of piping. The way I did it here or to run one supply and split it to two mains...........I have two equilizers and more than 28 inch "A" dim. this should work better than the other way. If the steam is slower and dryer this should "work" (the best way). I do not wish to waste Eds time so any other coments are welcome too........I wonder if.......the steam is dry in 28"? If so why the extra header on the boiler? If the steam is wet and needs the header for that reason could it just be a dirty boiler? I would rather put on the extra header.