Low water mark

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Emfinger
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Joined: Tue Oct 01, 2019 3:30 pm
Location: Yucca Valley, CA

Low water mark

Post by Emfinger » Mon Nov 18, 2019 7:04 pm

Hi guys, I got my bagley burner working well thank you all. I have my water too high (I think).

Will you please look at the picture and tell me where you think the low water level mark should be.

Thank you
Tom
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Marty_Knox
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Re: Low water mark

Post by Marty_Knox » Mon Nov 18, 2019 7:25 pm

Where is your crownsheet? Low water mark should be at least 1/2" above the highest point of the crown on your steepest grade.

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NP317
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Re: Low water mark

Post by NP317 » Mon Nov 18, 2019 8:53 pm

What Marty said.
Make sure to measure from the top of the crown sheet, not from the bottom which is accessible through the firebox door.

On my Mikado I had to blank out the bottom of my water glass to get that 1/2" above measurement. The crown sheet is higher than I wanted.
On the attached picture you can see the "crown sheet" label, but I had not yet blacked out the bottom 3/16" of the water glass.
I think this is a really important safety consideration.
RussN
Plumbing 1 sml.jpg

Emfinger
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Location: Yucca Valley, CA

Re: Low water mark

Post by Emfinger » Tue Nov 19, 2019 8:50 am

Mine is an oil burner, the crown sheet is flat, and if I use the 1/2"above rule there isn't any room for steam above that line.

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Fred_V
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Re: Low water mark

Post by Fred_V » Tue Nov 19, 2019 8:55 am

That's what the steam dome is for.
Fred V
Pensacola, Fl.

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cbrew
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Re: Low water mark

Post by cbrew » Tue Nov 19, 2019 9:35 am

Emfinger wrote:
Tue Nov 19, 2019 8:50 am
Mine is an oil burner, the crown sheet is flat, and if I use the 1/2"above rule there isn't any room for steam above that line.
maybe a sq picture of the back head with a ruler,

also stick you finger in the fire box door and get a measurement from the bottom of the crown sheet to the top of your firebox door.
it should be safe to assume the crown sheet is .375 thick, then add .5, this needs to be the low water mark.
If it is not live steam. its not worth it.

Emfinger
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Location: Yucca Valley, CA

Re: Low water mark

Post by Emfinger » Tue Nov 19, 2019 10:32 am

I have done that and the result is no room for steam. Water comes out of the smoke stack when the throttle is opened. Lots of water !
Also water exits the pressure relief valves that are mounted on the steam dome. When I switch from compressed air to steam for the atomizer I can't keep the fire lit, due to water in the atomizer line. The atomizer steam comes from the steam dome.
Are crown sheets normally flat?

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cbrew
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Re: Low water mark

Post by cbrew » Tue Nov 19, 2019 10:38 am

yes, for the smaller locomotives,
so how high is the crown sheet?
much have water over the crown sheet at all times. hence the the request above.
If it is not live steam. its not worth it.

Pontiacguy1
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Re: Low water mark

Post by Pontiacguy1 » Tue Nov 19, 2019 4:46 pm

It is not unheard of for someone designing a boiler to try to pack in an extra row of tubes and end up putting the crown sheet up too high, not leaving much room for steam and water space above it. I have run engines like that: They tend to be very finicky and tricky, and you have to constantly add water a little bit at a time to them so that you can both keep the crown covered and keep it from carrying water over into the dome. Add to that going up and down grades and the water sloshing around inside of the boiler, and it makes for an engine that takes a lot more attention and skill and is not very forgiving.

Like others have said: the crown sheet MUST stay covered with water at all times, no exceptions. So, making sure that you have enough water in the boiler to keep your crown sheet covered (usually 1/2" above it), is where the bottom of your glass should be.

Emfinger
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Location: Yucca Valley, CA

Re: Low water mark

Post by Emfinger » Wed Nov 20, 2019 9:44 am

You hit the nail on the head !
If that isn't bad enough, this is an oil burner.
Oh, my first run on rails will be in two weeks, wish me luck.
Thank you
Tom

Glenn Brooks
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Location: Woodinville, Washington

Re: Low water mark

Post by Glenn Brooks » Wed Nov 20, 2019 12:14 pm

Tom,

Oil might be an advantage with your boiler. There is another thread or two about oil. Most people say oil generates a lot of heat, more quickly than other fuels. Could be a real advantage where you have limited steam space and need to replenish often.

Have fun!

Glenn
Moderator - Grand Scale Forum

Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge

Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....

Mike Walsh
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Re: Low water mark

Post by Mike Walsh » Wed Nov 20, 2019 12:42 pm

You mentioned that the atomizer line keeps filling with water when firing. This is likely due to condensate of steam in your atomizer line.

I started the practice at the WF&P of cracking our steam-up blower hookup valve (which is at the lowest point of the cab piping) on our #534, to allow condensate to escape. I only crack it enough to allow steam to wisp out... The thinking is that since steam keeps escaping, condensate will escape in this area as well. You can crack it open even more, but then that is just wasting steam.

You may want to add a tee with a needle valve in your line somewhere to allow steam to escape. this may help with your water/atomizer line issue.

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