pitch on a 1 pipe steam main

mike jones_2

thank you both for your replies.

we dont belive there is any water leak as this is a new boiler and we tested for leaks by over filling to release water out of the pressure releaf tap and no water came out anywhere else.

we have a gas gun power burner and not atmospheric but i expect any leaks would still have been obivious.

the combustion anylizer gave 383 degrees f which i assume must mean stack temp.

the ancient boiler before it had a hole in it which is why we thought the wet steam would be behind us by now.

is there anything else we should check.

the ph is good no, bouncing or froth in the gage but very hard to get even 1 lb of pressure.

mike jones_2

pitch on a 1 pipe steam main

pitch on a 1 pipe steam main

is it ever ok to pitch a 4 inch steam main downward away from the boiler at a downward pitch before rising then up to a riser?

the main piping is larger than required in circumference, but it does not seem that this is ever ok to do in reading Dan's book, unless i missed an exception. the 6699 sq. ft townhouse only has 1011 sq. ft. of radiation and the above boiler piping is as per manufacture smith boiler specs.

Steamhead (in transit)

Do you mean

the steam main, which feeds branch lines that go to radiators?

Or is this the boiler header, which receives steam from the boiler and sends it out to the mains?

Take pics if you're not sure, and post them here. We'll get you straightened out.

In the pic I attached, the riser from the boiler (on the right) feeds a horizontal (with a slight pitch) header. The header then feeds two steam mains, and the vertical pipe on the left is the equalizer which drops to the Hartford Loop connection.

And yes, that's also a Smith boiler.

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mike jones_2

1 pipe steam main pitch

our piping is like yours, the riser from the boiler feeds a horizontal (with a slight upward pitch) header. The header then feeds two steam mains, 1 in each direction, insulated with the white fiberglass tube insulation like in your picture as well.

It is these 2 mains which then feed the vertical risers which lead to the radiators in the 4 corners of the 5 story building. we also have the equalizer which drops to the Hartford Loop connection.

these 2 mains have the slight downward pitch away from the boiler which is surprising us. btw, although it is impossible to tell from a photo, it does appear that the insulated main to the right in your picture slopes upward away from the boiler while the main on the left appears to slope downward away from the boiler.

thank you for your input.

Steamhead (in transit)

That pitch is correct

In this type of steam system, the condensate (water) from the radiators flows back into the steam mains. The downward pitch of the mains allows the steam and condensate to move in the same direction, which increases the mains' capacity and helps avoid water hammer (banging). At the end of each main, you should find a pipe that drains the water back toward the boiler.

While you're looking at your mains, check to see that there are properly-sized air vents at or near their ends. When sized correctly these vents save a lot of fuel.

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mike jones_2

steam pitch

thank you, that makes alot of sense, and yes each main drains to the wet returns. we replaced the main vents last year with the large gortons before we replaced the boiler with a properly sized smith and insulated the pipes.

crazy thing is we still have wet steam out the chimney, but no water hammer. pressuretroll is set at 1 pound but it never gets there, only turns off on heat timer cycle. we are now changing all vents based on radiator size, not location, as dan's book suggests, but still cant figure why big radiators on lower floors would be hard to make hot!

we thought maybe it was wrong pitch on the mains but are atleast glad that is correct. back to the drawing board. thank you steamhead!

bob young

leak

if you are getting wet steam out of chimney , there must be a leak at crown . leak between sections or crack

Steamhead (in transit)

Either that

or it's condensation in the flue gases. What is your stack temperature?

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Steamhead (in transit)

What model

Smith boiler do you have?

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mike jones_2

Smith b19a-s-3 steam boiler 375,000 btu

Smith b19a-s-3 steam boiler 375,000 btu
Power Flame JR15A 10-00 gas burner