Lap seam, riveted boilers

Where users can chronicle their builds. Start one thread and continue to add on to it.

Moderators: Harold_V, WJH, hwboivin3

Post Reply
John Landrum
Posts: 30
Joined: Fri Feb 17, 2017 2:05 am

Lap seam, riveted boilers

Post by John Landrum » Sun Feb 19, 2017 2:58 pm

I have one of the above lap seam, riveted boilers on an engine I am restoring. My question is, how to check the structural integrity of the rivets to know whether or not they are solid inside their holes or look like an hour glass and are just waiting the opportunity to become a high speed projectile when the boiler is put under steam pressure. Any thoughts?

User avatar
Marty_Knox
Posts: 1329
Joined: Thu Jan 09, 2003 6:50 pm
Location: Michigan, USA

Re: Lap seam, riveted boilers

Post by Marty_Knox » Sun Feb 19, 2017 4:46 pm

I would be more concerned about the lap seam itself. You can use dye penetrant to check for cracking.

Soot n' Cinders
Posts: 715
Joined: Wed Jun 27, 2012 5:24 pm
Location: Marietta, Georgia

Re: Lap seam, riveted boilers

Post by Soot n' Cinders » Sun Feb 19, 2017 4:57 pm

My question is how many rows of rivets are in the seam? As long as it's more than one, I would think a hydro test would be a good starting point
-Tristan

Projects
-2.5" scale Class A 20 Ton Shay

User avatar
Dick_Morris
Posts: 2155
Joined: Sat Jan 04, 2003 2:09 pm
Location: Anchorage, AK

Re: Lap seam, riveted boilers

Post by Dick_Morris » Sun Feb 19, 2017 5:48 pm

Bore scopes that you can use with a cell phone are cheap and can be used to inspect the interior.

How big of a boiler are you talking about? Steel or copper? What is the design (i.e., locomotive, vertical fire tube, or ?)?

User avatar
NP317
Posts: 1478
Joined: Tue Jun 24, 2014 2:57 pm
Location: Northern Oregon

Re: Lap seam, riveted boilers

Post by NP317 » Mon Feb 20, 2017 11:19 am

Best test method is probably ultrasound.
I'm not sure what modern improvements offer, but "shear-wave ultrasound" used to be the chosen method for looking "sideways" into rivet seams.
~RN

John Landrum
Posts: 30
Joined: Fri Feb 17, 2017 2:05 am

Re: Lap seam, riveted boilers

Post by John Landrum » Fri Feb 24, 2017 1:36 am

All good info guy's! To fill in the blanks, the boiler is for an 18" gauge locomotive and is about 6 feet long (the pressure part) there are three rows of rivets on the engineers side of the boiler and they run the length of the boiler from the rear tube sheet to the smoke box front. I would guess the diameter of the rivets at a minimum to be 1/2" the heads are conical and about 1/2 dollar size. I will post some photos of the boiler seam tomorrow.

Post Reply