Steam dome seal

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jlakes85
Posts: 147
Joined: Thu Feb 23, 2012 6:07 am

Steam dome seal

Post by jlakes85 » Sun Oct 22, 2017 5:09 pm

Hi all,

I finally finished rolling in all of the tubes and wanted to do an initial test on air at 20 psi. Low and behold the dome flange joint leaks. Upon further investigation, I determined that there's a "rock" between the flange and dome base and when rocked to one side shows a 0.010 gap. I'm guessing the flange distorted when welding. I tried using a 1/32 thick steam rated gasket however I couldn't get it to seal. I got a print on the steam dome bottom at the surface plate and it's perfectly flat. The flange/dome joint is now curing with permatex ultra copper and loctite 567 on all screws. Is there another method I should look at if this doesn't work?

-jlakes85

Pontiacguy1
Posts: 713
Joined: Thu Apr 26, 2012 10:15 am
Location: Tennessee, USA

Re: Steam dome seal

Post by Pontiacguy1 » Sun Oct 22, 2017 6:19 pm

Try chucking the whole dome cap up in the lathe and taking a face cut across it to true it up. I always do that with the steam dome caps after welding. If you leave it just a bit rough when you machine it, it will help that gasket get a good bite as well.

jlakes85
Posts: 147
Joined: Thu Feb 23, 2012 6:07 am

Re: Steam dome seal

Post by jlakes85 » Sun Oct 22, 2017 6:23 pm

I checked the dome base on the surface plate and there was no rocking. I'm thinking the distortion is in the flange surface

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Fender
Posts: 2424
Joined: Wed May 02, 2007 8:33 pm
Location: Chattanooga TN

Re: Steam dome seal

Post by Fender » Sun Oct 22, 2017 7:42 pm

Suggest putting Dykem blue (or similar) on the base and dome, and rubbing the two together with some lapping compound. The high points will show as bare metal. Scrape or file them down and repeat until there are no high spots.
Dan Watson

jlakes85
Posts: 147
Joined: Thu Feb 23, 2012 6:07 am

Re: Steam dome seal

Post by jlakes85 » Sun Oct 22, 2017 9:25 pm

Fender,

Gotcha. That's my next move if the ultra copper doesn't hold up.

Harold_V
Posts: 16434
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Steam dome seal

Post by Harold_V » Mon Oct 23, 2017 1:35 am

Ten thou on a large surface will not be fun to remove.
If the boiler isn't mounted, you might consider fly cutting the flange surface. You'd be better served spending your time making the mill setup than struggling with a surface that won't be easy to flatten. Fly cutting will yield a very flat surface if addressed properly.

H
Wise people talk because they have something to say. Fools talk because they have to say something.

jlakes85
Posts: 147
Joined: Thu Feb 23, 2012 6:07 am

Re: Steam dome seal

Post by jlakes85 » Mon Oct 23, 2017 5:43 am

Harold,

Sounds good..I was over at the HF website double checking the reviews on the 1000lb hydraulic table cart. I'm keeping my fingers crossed that the Ultra Copper gives me a pass on this one. Has anyone used that stuff for steam dome sealing before?

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makinsmoke
Posts: 1728
Joined: Thu Jul 10, 2003 12:56 pm
Location: Texas Hill Country

Re: Steam dome seal

Post by makinsmoke » Mon Oct 23, 2017 6:25 am

Not a hijack but you mentioned a hydraulic cart.
I have one of their orange ones. Not sure of the rating.

Beware of their wheels. If you have a shop with a perfectly clean floor and will never get gravel or chips on it no problem. I had gravel tossed into the garage shop and rolling the cart with the hard plastic wheels on a few pieces of gravel
tears them up. I know, cleanliness and Godliness, but I live in the country, the shop doubles as a garage, and I have dogs.

Solid steel wheels would have been a better choice for me had I known.

Back to the topic. How do you get a fly cutter into a 1-1-2" scale boiler?

Tks,
Brian

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makinsmoke
Posts: 1728
Joined: Thu Jul 10, 2003 12:56 pm
Location: Texas Hill Country

Re: Steam dome seal

Post by makinsmoke » Mon Oct 23, 2017 6:26 am

One other cart issue. It has bled down from day one.

jlakes85
Posts: 147
Joined: Thu Feb 23, 2012 6:07 am

Re: Steam dome seal

Post by jlakes85 » Mon Oct 23, 2017 7:08 am

Makinsmoke,

Thanks for the heads up on the cart. The surface with the issue is the top of the dome flange itself, so no problem with cutter access..I will have to squeeze around the exposed throttle and turret piping, bit shouldn't be an issue with a 1.000 dia insert cutter

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Fred_V
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Joined: Sun Jan 12, 2003 3:26 pm

Re: Steam dome seal

Post by Fred_V » Mon Oct 23, 2017 7:28 am

It's not easy to mount a boiler on the mill and get it perfectly square. Keeping it from moving is tough too. I've done it a couple of times. Once made two saddle blocks to go under the barrel. That made it level lengthwise. I used heavy chain and draw bolts on the T nuts to hold it down.
Good luck.
Fred V
Pensacola, Fl.

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FLSTEAM
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Joined: Sun Jan 05, 2003 10:55 am
Location: Central Florida
Contact:

Re: Steam dome seal

Post by FLSTEAM » Mon Oct 23, 2017 9:37 am

Another direction would be to cut the studding flange out then true it in the lathe again.
Re weld it back in place but this time be sure to tack it in place with lots more tack before the root pass.

John B
http://www.ngshay.com/
Shay drawings and castings

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