Size of weld with shell & pad 3

[MicroEng]

hi all
i know that uw-16.1 tell the minimum of weld size between
shell & pad &... (.7 t(min)) . but what the maximum of it?
can i weld them with t(min) or (max)?
tankx all

 

[aclark]

Section VIII does not place an upper limit on the weld size. The minimum weld size is a function of the location of the weld i e if the nozzle has a pad etc. and the thikcness joined.

tmin is the smaller of .750 or the thinner if the parts joined. tc is the smaller of .250 of .7tmin.

 

[deanc]

Be careful here. See ASME SecVIII UW-15,UG-41,UW-35. The thinner of two parts joined is not always the correct answer.

Too large a weld can result in lamellar tearing and stress risers at the face.

 

[aclark]

UW 35 contains the requirments for max reinforcement at long and circ joints. It does not have anything to do with fillett welds.

UW 15 and UG 41 contain requirments for calculation of weld and attachment strength.

UG 16 has the rules for attachment weld size. However I do agree that if a fillet weld is extremly over sized it could cause a stress riser in the attachment.

 

[deanc]

Agree it is not UW-35,should be UW-36.

If you read the words in UW-15,first sentence,this paragraph is mandatory for reinforcements.

UG-41 is also mandatory.

UG-16 deals with material thickness. Were you refering to UW-16? This does not deal with re-pads.

If you use a re-pad,you must address ALL of the requirements.

 

[aclark]

UW 36 has the requirments for penetration of a fillet weld at its root, also it must meet the same requirments as a groove weld for undercut.

UW 15 contains the requirements for weld strength. as required by UG 41. UW 15 also exempts some welded attachments from calculation of weld strength, but not those that contain added reinforcement elements. (such as pads)

UW 16 contains the requirments for location and minimum size of attachment welds for nozzles and other connections.
you must apply all of the rules in UG 41 UW 15 as well as UW 16 to insure that you have a opening in the vessel that meets Code requirments. If you run some calculations that have under size fillett welds you could have a weld which will develop the required strength but would not meet the mimimum size of required by UW 16.

Note the title of UW 16, "MINIMUM REQUIREMENTS FOR ATTACHMENT WELDS AT OPENINGS"

As an Inspector as well as an ASME/Nat'l Board Team Leader I cannot require more than the mimimum requirments of the Code.

 

[LSThill]

Hi MicroEng (Mechanical)

I agree with Mr. aclark (Mechanical, Note: Mr. aclark, Is the technical instructure on the following BOILER AND PRESSURE VESSEL COURSE: "NBIC"

http://ccs.goivytech.net/boiler_pressure/

Welcome to the Ivy Tech State College Boiler Pressure Vessel Training course scheduled for February 16 - February 28, 2003. I am the course manager and am here to answer any questions that you might have. If you have not already, you may want to go to our website at

http://ccs.goivytech.net/boiler_pressure

for more details on the course and what books you will need to bring with you. There is also information regarding hotels. The instructors (Dan Willis and Allan Clark) will be staying at the Hampton Inn here in Terre Haute and we recommend that students stay there also, if possible. We have reserved a block of rooms, with a special room rate, for this course, should you decide to stay at the Hampton. Evening study sessions and access to instructors tends to be more convenient. Be sure to let your travel agency know to advise the Hampton Inn that you are in the Boiler Pressure class.

I will be sending you information on Terre Haute, In. Since Terre Haute does not have any direct commercial commuter flights, you will need to fly into Indianapolis and take a rental car to the hotel. Class will start on Sunday, February 16, at 1:00 at the Ivy Tech State College Airport Campus located at the Terre Haute International Airport, 501 S. Airport Street, Terre Haute, IN. Maps on our website will show hotel and campus locations.

Should any questions arise in the interim, please let me know.

Joseph P. Zinkovich, Manager
Ivy Tech State College
501 S. Airport Street
Terre Haute, IN 47803
812-298-2363
812-877-1184 - Fax

http://www.goivytech.net

Leonard@thill.biz

http://www.thill.biz

 

[MicroEng]

hi all
i use all of ur helps.
Mr.aclark i agree ur idea & use that.
thanx all.

 

[LSThill]

HI MicroEng (Mechanical)

You may want to have a beter understanding of the ASME CODE the next coures in offered in at Ivy Tech State College Boiler Pressure Vessel Training course scheduled for May 18 to May 30 2003.

http://ccs.goivytech.net/boiler_pressure

Should any questions arise in the interim, please let me know.

Joseph P. Zinkovich, Manager
Ivy Tech State College
501 S. Airport Street
Terre Haute, IN 47803
812-298-2363
812-877-1184 - Fax

http://www.goivytech.net