RE: 1175] TKY Joints definition and use of 6GR Welders

[Bathula Raghuram (Mumbai - PIPING)]

In my opinion "NO" , considering that these joints (Access platform, ladders) welded with Fillet only, and not with either CJP or PJP.

 

what is type of connection as defined in para 4.26, 4.27, 4.28 of AWS D1.1, is it CJP, PJP or fillet?. In this regard your designer is handy to clarify, what criteria used for designing these accessories, essentially in my opinion no designer will use para 2.24 to calculate Punching shear, LRFD etc for ladders, access platforms. This para 2.24 is applicable only for strength welds in statistically or cyclically loaded connections.

 

If you refer commentary C4.12 (2) (d)  states "Fillet weld TKY connections can be executed by welders having even lower level of qualification.........  ''

 

I am not using D1.1 on day to day hence I may be wrong in my views expressed here, however these can't be presumed to match the strength of members joined, but shall be checked by the designer for specific applied loads in conformance with 2.24.2.3, 2.20.6, 2.23.1, 2.24.1, 2.24.2.

-----Original Message-----
From: material...@googlegroups.com [mailto:material...@googlegroups.com]On Behalf Of Vinod Upadhyay
Sent: Tuesday, September 30, 2008 6:35 AM
To: material...@googlegroups.com
Subject: [MW:1175] TKY Joints defination and use of 6GR Welders

AWS D1.1/D1.1M :2006 para 2.24.1.5 (2) , attached, states that classification criteria of TKY joints is based on punching load cases of brace to chord connection.

Now the question is that:

The given weld connection is tubular to tubular (TKY type) but does not fall under TKY classification based on punching load cases as para 2.24.1.5.
for example secondary and miscellaneous small structures like access platforms , stairs  etc fabricated by tubulars/ pipes.
Do we need to treat these tubular to tubular joints as TKY joints and strictly welded by 6GR qualified welders??


--
Thanks

Vinod R Upadhyay
SMOE (a subsidiary of SEMBCORP MARINE)
Batam Yard, QA/QC- TOTAL Project
Mob:+62 815 1474 1550

[Vinod Upadhyay]

Even if a joint does not fall under TKY category as per para 2.24 regarding calculation of punching load. But still the design is based on CJP .
Under such condition if the given tubular weld is a CJP and there is a restriction for welder during welding , it shall qualify for 6GR Welding and must be welded by 6GR welder irrespective of punching /shear loads. As far as welding and welder qualification is concerned AWS D1.1 are not differenciating CJP TKY  joints based on TKY defination given in para 2.24. For welder qualification we must follow para 4.26 and fig 4.27.  It is all due to welder welding with restriction.
Please confirm if my understanding is correct.