I have seen many butcher jobs that are not obviously listed in the Code because no engineer would think anybody could be that stupid.



“PG-82.1 Threaded (staybolt) holes shall be tapped fair and true with a full thread.”
When the manufacturer specified the thread profile, USF, Whitworth, that invokes the ANSI standard and all that goes with it. Major, minor pitch diameter, lead, lead error, etc.



The Code says the staybolt must able to carry its design load. Just suppose there are four staybolts in a row except one has a bend in it. 3 straight, one with a bend in it. In the shop, the AI should ask to see the calculations to prove that as the boiler is pressurized; the bent stay will not deflect, thereby reducing its load carrying capability. The straight bolts obviously will not deflect. It is the manufacturer’s responsibility to prove the adequacy of the curved staybolt design. The shop inspector should have caught this. Now the National Board should be advised. The boiler never should have left the shop. Without a superbank of computers to prove the design, then PG-100 comes into play where the manufacturer builds a duplicate to test to destruction to determine MAWP.


As far as washouts are concerned you can always add more. The ASME Code only addresses safe design when new. It does not address thermal efficiency or a long maintenance free life.



Just because it has a stamp on it does not necessarily mean it meets Code, unfortunately.

PS
Mark,
Looks like you have some 'red-tagging" to do tomorrow.

Doesn't Matt have the coolest pictures.......

I remember seeing a really humorous one about curved stays several years ago at the TRAIN convention.

dave

All,

In regards to Matts' pictures of the firebox, I have seen a traction engine boiler built by the same company(whom is now heading up the boiler design and fabrication of a new construction locomotive project) that had "S" curve staybolts and longitudinal stays in hard contact with the highpoint of the crown.

In regards to stays being in time. There was much debate regarding this subject in the later years of the steam era and the going opinion was that the time was never off enough to matter. Not sure I buy into that, one can easily utilize one of Mr. Yuills taps as a crown stay tap...even easily keeping the threads in time.

Matt,

I'm not arguing with anything you said, but I'll tell you I've seen some doozies. PG82, in all it's glory, still doesn't tell the unknowing shop to "time" the sheets......you can tap each sheet independently, and force the bolt. Regarding AI work.......I've seen data plates on backwards (data facing vessel / back of plate facing inspector). Each time I see something I think to myself "Now how the hell did THIS happen??" Yet, each day brings something new.

A 2' gauge locomotive (new construction) here passed and has it's stamp, but I could spend pages talking about all that I think is wrong with it.

These issues are common and not specifically related to locomotive or traction engine boilers. Everyday wet back scotch marine boilers usually have misaligned stays, and sometimes bent, too. When the boiler is one of "special" construction (i.e. locomotive / traction) and the constructing shop isn't geared up and knowledgable, well let the creative construction begin!

Mark

Just how big are those stays, as they don't look much bigger than 1/2"? And what I want to know it, what AI looked at that said, uh, looks good to me......

what really gets me is they went to the trouble to flange the sheets, and then just flat out cobbed the rest of it up.

I would love to see the engineering drawings on that, and how that mess was calculated.

BTW was just visiting with a friend with a boiler shop that does some historic boilers, and I am of the opinion that a boiler with welded long seams, and rivited circumferential is a good comprimise when a historic look is desired.

Hi All

I just received word that Marty Westland of Ely, Nevada, is on the ASME committee and will be in Strasburg, Pennsylvania. Do we anyone know who the other members are?

Robby Peartree

Robby,
Are you refering to the NB Special Subgroup for Locomotive Boilers, or is there another A.S.M.E. Group?
The NBIC 07/09 Addenda list the following people:

B. Withuhn
S. Butler
D. Conrad
R. Franzen
D. Griner
S. Jackson
M. Janssen
S. Lee
D. McCormack
L. Moedinger
R. Reetz
G. Scerbo
R. Schueler
R. Stone
R. Yuill

Is the new guy an addition, or a replacement for someone?

Hi Nathan

Here is the list I have

Name Of Member, Com Exp Date
Chair Linn Moedinger, 6-30-2012
Mr. Paul Boschan, 6-30-2014
John Braun, 6-30-2014
Steven M. Butler, 6-30-2014
J. David Conrad, 6-30-2014
Robert C. Franzen Jr., 6-30-2014
Mr. David W. Griner, 6-30-2014
Steven D. Jackson, 6-30-2014
Matthew A. Janssen, 6-30-2014
Gregory M. Ray, 6-30-2014
George I. Scerbo, 6-30-2014
Robert D Schueler Jr., 6-30-2014
Richard B. Stone, 6-30-2014
Martin W. Westland P.E., 6-30-2014
William L. (Bill) Withuhn, 6-30-2014
Robert Yuill, 6-30-2014

It is interesting to see the differences. I hopw the people on the committee make it a point to open up the discussion of what they are doing and we have some form of a report.

Robby Peartree

There was a post on this topic last night (4-10-2010) that is not here today by somebody who may not have all or accurate information on the new ASME Subgroup on Locomotives. It is not hard to understand some of the misperception as a number of the members of the National Board group are also in the ASME group (see above lists). The American Society of Mechanical Engineers, Boiler and Pressure Vessel Code is an approximately 20,000 page document that provides rules and standards for the new construction of boilers and pressure vessels. The National Board Inspection Code provides rules and standards for the operation, inspection, repair and alteration of boilers and pressure vessels. One good way to draw a mental dividing line is new versus post construction activities. Where these lines get blurred is when the most recent edition of the ASME Code is used to provide the rules of construction for a repair or alteration of an existing boiler or pressure vessel. The new ASME Subgroup will only deal with issues relating to new construction.

I apologize to the Moderators for mentioning a deleted post. I thought other members of the community may be confused by the close relationship of the various groups and committees that deal with locomotive boilers so I wanted to share what little I know about this topic in the interest of clarity.

S.O.

Dear Mr. Ottaway

Thank you for the clarification.

Robby Peartree

Stan;
You are exactly right. The issue of late has been problems with the construction of new replacement boilers of late. This is something the A.S.M.E. appears to be looking at finally. The N.B.I.C. has the repair procedures down pretty good until lately. What I have found amusing, is that if I build a new boiler to Section I, and have to repair it two years later, I am not allowed to use the same materials that the boiler was built with, but must use some "unobtainium" from some hard to find source.
Regards, Nathan

The deleted post was deleted by the original poster.

Moderators have occasional back channel discussions about posts... Generally this occurs when we have concerns that the post is on the margin of our guide lines, but has not crossed (yet)

We also look at the information included... a post that is close to the edge of the rules, which also includes a strong well said point of view with good information is likely to stay.

This thread, and the lap seam boiler thread are providing great information. Occasionally both are close to violating guidelines, there are strong points of view expressed, but the information is so good.

Our goal is not to moderate... it is to guide... There are lots of posts that make the hair on the back of my neck stand up... but...

Your always friendly moderator, (In memory of Kevin Gellespie)

Hi
I am from Tasmania Australia and interested in most of the comment in this thread. Fillet welded boiler stays in steam locomotive boilers have been in use here from about 1949 and pretty well conform to welded stays in the current Australian Standard AS 1228-2006 Pressure Equipment - Boilers. I have drawings produced by the Government Railways of the period
Not being technically gifted as some contributors I would say fillet welded boiler stays here have passed the test of time without catastrophic failure.

However one should consider the danger of welded in Arch Tubes which the National Board of Inspection Code allows (Part 3 - Repairs and Alterations S1.2.9.2).
The fear here (Australia) is because of relatively thin walled tubes (7swg) and relatively thin firebox plate thickness (3/8th"), The rapid and varying fluctuations in pressure and temperatures, plate and tube movement could cause a fracture with the potentia for disastrous results.
What has the experience been for Heritage Railways in the United States that use welded in Arch Tubes?
Maybe Arch Tube discussion ought to be moved to a new thread??

The NBIC in Part 3, Section 1.2, paragraph (a) reads, "When the standard governing the original construction is the ASME Code or ASME RTP-1, repairs and alterations to pressure retaining items shall conform, insofar as possible, to the section and edition of the ASME Code most applicable to the work planned." This allows the use of the original edition/addenda of the Code for your repairs. If you used SA-516-70 pressure vessel steel plate for the original construction, but the current Code did not allow it (don't worry, SA-516-70 is still very much allowed for boiler plate) you could still use the original material specification and the original allowable stress for the repair or alteration.

Nathan, I would like to know more about the situation you described. Contradictions within the Codes crop up from time to time so for the sake of my own education, I’d like to know more.

Thank you for your contribution to the discussion.

S.O.