From: Keilbach, Robert [Robert.Keilbach@wgint.com]
Sent: Tuesday, March 14, 2006 1:00 PM
To: Thomas G. Brown
Subject: RE: Weld size

Tom,
Shop likely used ER70S-2 filler metal, which has min. UTS and YS of 70 and 58 ksi respectively.

The purpose of the AISC/AWS - specified minimum fillet weld sizes is to provide sufficient welding heat input to retard the weld cooling rate in heavy wall thickness C-Mn steel materials, regardless of loading. However, please note that per AWS D1.1-2002 Table 5.8 Note 1, based on the use of GTAW, which is a low-hydrogen welding process, a minimum fillet weld size of 3/16" is acceptable, unless a larger weld size is required by design.

Bob
X2661 


-----Original Message-----
From: Thomas G. Brown [mailto:tbrown@pppl.gov]
Sent: Tue 3/14/2006 12:14 PM
To: Keilbach, Robert
Subject: Weld size
 
Robert,
 
I need some weld engineering guidance.  The weld in question is shown sheet 3
of se184-002, 03 and 04 Assemblies.  I also have an accompany spreadsheet
attached where I've done some back-of-the-envelope calculations on this
weldment to see what load capacity it had in supporting the load of the
vacuum vessel.  We will be supporting the 5,125 lb VV from this assembly with
a 10,000 lb rated swivel hook (not shown).  The drawing shows a 3/16" bevel
weld between a 1" top plate and the 5.5" OD tube (1/2"wall).  It turns out
the shop used a 3/16" fillet weld to join the parts.  My calculations
indicate that the 3/16" weld is okay, however according to AISC/AWS codes the
minimum weld size is 5/16" (determined by the thickness of the thicker part
joined, but does not need to exceed the thinner part joined).  In one
calculation I assumed an E60 filler material.  I later found that the shop
used a filler ER70-552, which I could find material data.  I talked to the
weld tech and he thought that a 5/16" would be a very big weld to put on this
part.  It appears that the weld joint is stronger that the hook load capacity
even assuming that the hook caries a 50% margin. What are your thoughts on
this?  The job charge to use is: 9450 1*** 1803.
 
Tom
 
Tom Brown
Princeton Plasma Physics Lab
PO Box 451
Princeton, NJ 08543-0451
 
Phone: (609) 243-2156       fax: (609) 243-3030