Shear lug sizing/WRC-107 1

[4fletch]

I'm trying to correctly size shear lugs for a Main Steam Pipe rigid hanger (donut clamp type). We are replacing a batwing style rigid hanger with a shear lug type. My understanding is that some of the calculations are based on data in WRC-107 and also reference Blodgett Table 5. Are these standards/specifications or what, and where can they be found? Thanx in advance for any assistance.

 

[JohnBreen]

Fletch,

WRC 107 is not going to help you. Omar Blodgett will not be much help either. Look at Pipe Fabrication Institute publication (Engineering Standard) ES-26:

Welded Load Bearing Attachments to Pressure Retaining Piping Materials.

For years we used to use a book of hangers standards that came out of the old Grinnell Company (NOT their catalog, this book was developed to do in-house seminars) and if you are lucky enough to find one of my contemporaries who is retiring ask him for his copy. That standard had a nice riser clamp design procedure in it. That book of standards gathered supports standards from various sources and it was widely copied (bad boys) and used.

Best regards, John.

 

[4fletch]

Mr. Breen, thank you for pointing me the right direction with your very helpful post. I'm sure ES-26 will be the most applicable reference document.

 

[LSThill]

Hi 4fletch (Materials)

The program and reference is WRC 298.

or FE-PIPE by Paluin Research Group

Leonard@thill.biz

http://www.thill.biz

 

[LSThill]

Hi 4fletch (Materials)

I do agree with Mr. JohnBreen (Mechanical) Also, the above reference to WRC 298 and the computer program with WRC 298 is a reference for ES-26.

Take a look at WRC 298

Leonard@thill.biz

http://www.thill.biz

 

[piping1971]

You can also use the Nuclear Code Cases N-122 and N-318.
These are code cases for Rectangular attachment for Class 1 and Class 2& 3 piping respectively.

 

[DSB123]

Hi 4fletch,
Blodgett reference will to one of two books written by him on welded structures. They are available from the Lincoln Welding Foundation. They cover many applications within welded structures including welded attachments on pipes. They are very low cost for the amount of information they contain. However I agree with Mr John Breen it's better to go with his references for shear lugs on pipework.

 

[LSThill]

Hi 4fletch (Materials)

Dear Sir's: JohnBreen (Mechanical), 4fletch (Materials), San4876 (Mechanical), DSB123 (Mechanical) I miss the reference is not WRC 298, but WRC 488.

WRC BULLETIN 448 Evaluation of Welded Attachments REPLACE WRC 198

Introduction

The purpose of this report is to summarize the background of Code Cases N-122-2 and N-318-5. Case N-122-2 is included in this report as am appendix. Case N-318-5 is Appendix E of report 2. Frequent reference will be made in the following text to these Cases. The definitions of symbols used in this report are those of the Cases. Other symbols are defined where used in the text and/or table.

N-122 and N-318 were first published around 1980; some four years after the publication of Welding Research Council Bulletin 198. The motivation if the development of N-122 is described by the following extract WRC198:

"A piping system design requires the specification of a corresponding support system whose function is to transmit force to the piping system or to limit its deformation. Structural attachments which connect the pipe system with its supporting elements are classified into two general categories, those integral to the piping system and those that are not . Lugs welded to the pipe are examples of integral attachments. whereas roller supports and various types of clamps are examples of nonintegral attachments. Article NB-3645 of Section III of the ASME Boiler and Pressure Vessel Code requires that the effects of attachments in producing thermal stresses, stress concentrations, and restraints on pressure-retaining members shall be taken into account in checking for compliance with design criteria."

The preceding quote is directly relevant to N-122 (Class 1 piping); WRC 198 covered only CLASS 1 piping. However,having a relatively simple method of calculating stresses at lugs, the analogous N-318, of the Class 2 and 3 piping, was developed.

During the years between 1980 and 1994, N-122-1 and N-318-1,-2,-3,-4, were published. These mostly involved clarifications of how to use the Cases. in 1994. N-122-2 and N-318-5 were published. These editions included a major change in that the coefficients of the equations of CT, CL and CN were divided by two. This report deals, in large part, with the bases for making this change.

The review of this report leads to several suggestions for revision N-122-2 and/or N-318-5. These are discussed in Sections 4.3, 4.4 and 4.5 of this report and are summarized in Section 8.


Regards to FE/Pipe "bend with Stanchion" page 1.8.4 compare to WRC Bulletin 448 January 2000 Evaluation of Welded Attachments on Pipe and Elbows

Report 1: Background and Suggested Revisions:
ASME Code Cases N-122-2 and N-318-5 "Lugs on Straight Pipe" , E.C. Rodabaugh & E.A. Wais
Report 2: Evaluation of Welded attachments on Pipe and Elbows
E.C. Rodabaugh
E.A. Wais
G.B. Rawis

 

[MJCronin]

4fletch,

Please e-mail me...

I have some old background information that may help you

mcronin@sdengineers.com