Steam Dome Cap Material To Use

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heislerboy
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Steam Dome Cap Material To Use

Post by heislerboy » Sun Mar 14, 2021 11:08 pm

What type of steel do I need to use for the steam dome cap? My boiler did not come one and I bought the locomotive from the third owner of this engine. What I have been told is that the boiler was built by Colorado Boiler Company. By the way the locomotive is 2.5 inch scale 2-8-0.

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Fender
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Re: Steam Dome Cap Material To Use

Post by Fender » Mon Mar 15, 2021 1:16 pm

Are you referring to the “pressure” part of the dome, or the decorative shell covering the sides and top?
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heislerboy
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Re: Steam Dome Cap Material To Use

Post by heislerboy » Mon Mar 15, 2021 7:53 pm

Yes, the pressure plate.

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NP317
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Re: Steam Dome Cap Material To Use

Post by NP317 » Mon Mar 15, 2021 9:40 pm

Drawing or photo of what it looks like?
And of what it mates to?
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heislerboy
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Re: Steam Dome Cap Material To Use

Post by heislerboy » Mon Mar 15, 2021 11:07 pm

Here are some of the drawings of what it looks like and attaches to.
Dome cover_1.jpg
Dome cover_1.jpg (20.82 KiB) Viewed 2045 times
Here is what it looks like a top view of it and placement of holes.
Dome cover_2.jpg
What it attaches to on the boiler.
Dome cover_3.jpg
The red arrow is what I am talking about in this drawing.

I do know that it needs to be 4-1/2 inch round and 3/8 inch thick. This is also where you put the safety's and the whistle on.

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Bill Shields
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Re: Steam Dome Cap Material To Use

Post by Bill Shields » Tue Mar 16, 2021 7:29 am

A36 to be technically correct.

I would be more concerned about the specs of the hardware holding it in place.
Too many things going on to bother listing them.

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FLSTEAM
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Re: Steam Dome Cap Material To Use

Post by FLSTEAM » Tue Mar 16, 2021 7:45 am

Actually that part is considered part of the pressure vessel and should be SA-515-70. A36 is a mild steel and is used for stay bolts.
These are per the ASME code. Even if you are not building a code boiler why not use code material.

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Re: Steam Dome Cap Material To Use

Post by Frank6276 » Wed Mar 17, 2021 3:49 pm

Following up on Bill Shields hardware concern and note on the drawing that calls out a "stud", the stud should be per ASTM A193 Gr B7 and the nut should be ASTM A194 Gr 2H.
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Bill Shields
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Re: Steam Dome Cap Material To Use

Post by Bill Shields » Wed Mar 17, 2021 9:12 pm

I am a bit skeptical about a 'code' boiler design concern where they have you drilling and tapping into and past the welded joint for the steam dome...think about it.

It is probably OK..but...I would do it another way...unless the threaded holes are already there.
Too many things going on to bother listing them.

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