Lethal Service - Category D Full Penetration Weld Joint Type

My opinion is that for you to go to an anonymous forum to ask advice about anything having to do with "lethal service" is unprofessional!

Someone, somewhere will have to sign off on the process used. That should be an engineer certified by NFPA or some other agency. Not some unknown stranger on the internet.

You can copy this if it will help.

Good Luck!

My, my aren't we touchy tonight. PV Engineering offers these tips.

http://www.pveng.com/ASME/ASMEComment/WeldEffic/Weld_Efficiencies_Notes.pdf

Good luck with your quest.

Thanks for the useful link.However,I am still confused with the interpretation of the mentioned clause in my query!If you go through UW-2 service restriction clauses, you can find that it is clearly mentioned about type of joints about category A,B&C joints.Unfortunately there is no spectifc type of joints for Category-D !Do you have any idea about the 'type of joint' to be used in 'category-D' joint for lethal service??

"Except under the provisions of (a)(2) or (a)(3) below, all joints of Category A shall be Type No. (1) of Table UW-12"

"All joints of Categories B and C shall be Type No. (1) or No. (2) of Table UW-12."

"The finished stub end shall be attached to its adjacent shell with a Type No. (1) or Type No. (2) joint of Table UW-12." {Stub end joint comes under Category-C as per UW-3 and it shall be made as per figure UW-13.5}

"All joints of Category D shall be full penetration welds extending through the entire thickness of the vessel wall or nozzle wall.'

Thanks,

San

You apparently have Section VIII, Subsection B to reference. Please see UW-3 "Welded Joint Category". UW-3 (d) describes a category D weld. From there, please see UW-16 "Minimum Requirements For Attachment Welds at Openings" and refer to FIG. UW-16.1 for nozzles connection to shells or heads. You will find several illustrations for full penetration nozzle welds. The weld you describe will be illustrated in FIG. UW-16.1, whether using reinforcement plate material or using the inherent reinforcement of the nozzle. I hope this helps you. I have designed many "Lethal Service" vessels, most of which were for offshore H2S service in oil production environments. Many restrictions apply to the lethal service design. Some of these restrictions are stringent PWHT, hardness, and RT requirements.

Hi Robert

Now the question is,

Can I use single side groove weld (ie, weld without back gouging or backing strip) to weld nozzles to pressure vessel shell as per ASME B&PV Section VIII Division-I rules? (Welding from one side without back gouging are generally used this kind of weld in power piping (ASME B31.1, process piping (ASME B31.3 and cross country pipelines (ASME B31.4 & ASME B31.8.)

Following info. is only for info.

{As per ASME Boiler&Pressure vessel code Section VIII DiviSion-I, meaning of double sided weld (First, welding the groove from out side and then back gouge the root from inside and deposit one or two layer of weld metal on that back gouged portion to fill the weld metal. If possible flush grind it to avoid crevices}

by the way how long you are in this field ? I am curious...

Hiii, Robert the above mentioned diagram is called full pinitratshan beld.

Hiii Robert, oil and gas available in onshore also....

PWHT means just after welding or after 10 minutes , 30 minutes or 1 hour...

RT means , room temperature or Ultrasonic Testing?

Hardness means , dislokkation multiplication inside mathransite matrix in non heat affected sone?

SIR SIR ,

Do youu no the eppansion of ASME?

http://answers.yahoo.com/question/index?qid=20080818013733AABrI2d

Hope this helps

Dear Anonymous Poster #1..

I apologize if I have offended you! That was quite a volley of 12 assaults! But, what the heck, I'm 30+ years into ASME, Section VIII, have "U","R", and "S" stamps. I have gone thru harder times!

Be well and be good!!

Dear Robert,

really? only 30+? I thought that you have more than 60 years experience in this field!

To be frank, I never worked in any industry so far. however, how was my performance? was it below average, average, good, best or excellent according to your rating? Next week I am going to attend my first job interview in my life. By the way you didn't give answer for my question which I raised in post #8!

Best Regards

Anonymous#1