Reinforcement of Welded Branch Connections
Reinforcement of Welded Branch Connections
(OP)
Hi, I have a issue about a reinforcement design, acording to ASME B31.8. And is on point 831.41 General REquirements... specifically on section "e" "The area of reinforcement ...is defined as a rectangle whose length shall extend a distance, d, on each side of the transverse centerline of the finished opening and whose width shall extend a distance of 2 1⁄2 times the header wall thickness on each side of the surface of the header wall..." Appendix F figures5
The length of this rectangle is two times internal diam. (2*d), this measure is a maximun or minimun limit?
Can i do it shorter than 2*d?
thanks
The length of this rectangle is two times internal diam. (2*d), this measure is a maximun or minimun limit?
Can i do it shorter than 2*d?
thanks
Alejandro Fernández
I+D&I
Sitelca





RE: Reinforcement of Welded Branch Connections
This is a maximum limit. Your reinforcement may extend beyond this limit but you cannot take credit for area replacement which is beyond it. The reinforcing pad may have a smaller diameter than this limit, or if the area required is relatively small, may consist simply of a larger weld.
Not a likely scenario on pipelines, but on vessels it is not uncommon to have a reinforcing pad diameter exceed the area of reinforcement limits in order to accomodate piping loads on the nozzle. So one calc is performed for area of reinforcement which determines the area within the limits of reinforcement, another calc is performed to determine the stresses due to the nozzle loading.
jt
RE: Reinforcement of Welded Branch Connections
I have another question... ASME B31.8 allow me to use Weldolet on top of a reinforcement pad?... The final assembly look like a split Tee.
Alejandro Fernández
I+D&I
Sitelca
RE: Reinforcement of Welded Branch Connections
jt
RE: Reinforcement of Welded Branch Connections
Alejandro Fernández
I+D&I
Sitelca
RE: Reinforcement of Welded Branch Connections
If you need the reinforcment from both the Weld-O-Let and the Repad, then you should weld on the Weld-O-Let to your header first with the correct full pen weld(omit the backup fillet). Then after the Weld-O-Let is installed you can weld the repad to the branch connection. This will meet the code weld detail requirements.
RE: Reinforcement of Welded Branch Connections
Alejandro Fernández
I+D&I
Sitelca
RE: Reinforcement of Welded Branch Connections
Additionally (if I understand correctly) with your proposed arrangement, there is a crevice between the pad and pipe that is exposed to process fluid and pressure.
I don't like it at all.
John
RE: Reinforcement of Welded Branch Connections
RE: Reinforcement of Welded Branch Connections
I seen this arrangement in some refinery in Venezuela.
The main idea is perform a welding of the reinforcement pad to the header in the outside... Doing this the pad can act like a pipe... see Fig. I3 (Welding Details for Openings With Complete Encirclement Types of Reinforcement) on ASME B31.8
Your opinion plis.. ?
Alejandro Fernández
I+D&I
Sitelca
RE: Reinforcement of Welded Branch Connections
You say you have seen this type of arrangement on a refinery in Venezuela? Well it's an accident waiting to happen. I would not visit the refinery anymore!!
RE: Reinforcement of Welded Branch Connections
Just because this has been done incorrectly (and dangerously) in the past does not mean you can allow it to continue. We've always done it that way is a sorry excuse used to cover up the fact that it has been done incorrectly.
I would never allow that joint to be built into a system I was responsible for, if I saw it in a pipeline that I inherited; I would force its replacement at the next shutdown. This is a terrible joint configuration (and a blatant code violation) and as DSB123 says it is an accident waiting to happen.
RE: Reinforcement of Welded Branch Connections