Tube plugging 5

[niteshgargeck]

Hello

My question is there any standard or reference which gives exact guideline that whether we have to puncher a tube before plugging. This is the case of boiler where we have leak in a bend.
now can i remove the bend and plug the tube or i have to puncher the tube then plug it.

 

[bpv66]

The 2015 NBIC Part 3 will be addressing plugging of tubes in fire-tube boilers. Calculations will be required to determine the strength of the attachment weld. It also states tube plugs are "temporary", but does not specify the length of time the plug can remain in place. It is left up to the owner and the Inspector.

I don't think the rules go far enough. Apparently, many repair organizations lobbied against any rules being addressed in the NBIC. So we get a compromise.

 

[LittleEd]

Numberfive covered it very well!!! Most jurisdicitons adopt the NBIC rules for such repairs, and the problem has been there has previously been no requirements in the NBIC for plugging of tubes....so I am anxious to see what bpv66 has mentioned about the 2015 NBIC having some information on this topic (although don't know what they would only address plugging of firetube boilers).

When a tapered plug was "driven" into tube-end to plug a leaking tube many jurisdiction did not even consider this a code repair as no welding was required...owners might even perform such "temporary" repairs. I always heard when plugging tube by this method that you needed to make a good hole (blow a hole with a torch) in the tube to prevent pressure from possibly building-up in the tube and blowing the driven plug out.

In recent years I've seen much discussion about what material is required for the tube plugs - SA-105 has stress value equal to SA-516-70 (drums) whereas SA-36 material has lower stress value.