BTC-P4 weld effective throat

[YoungGunner]

I'm a bit confused on what the Steel Manual and the Specification are conveying about BTC-P4 welds.

Table 8-2 for BTC-P4 weld says that the base thickness for the metal may be "unlimited", yet the root face (land) is 1/8" min. Furthermore, the table says that the effective throat is S-1/8", which means you take off yet another 1/8" to the throat? So if we only specify a 1/4" thick plate, then we effectively get E=0 because we need 1/8" for the root face and 1/8" taken away from the effective throat?

This becomes further complicated when the Specification in table J2.1 says that the effective throat is the depth of the groove, which seems to counteract the information about S-1/8" for the effective throat.

Furthermore, Risa connection is allowing me to directly weld a beam flange to a column and use the entire flange thickness for the PJP welding. It's not specifically going for a BTC-P4, but still feels odd relative to the other information presented.

Can someone walk me through how all these pieces come together?

 

[phamENG]

So we're looking at a PJP, single bevel groove weld for a butt, T, or corner joint. (Page 8-55 of the 14th edition.)

Not sure why they call it unlimited. But it seems you worked out the technical minimum, so that's more-or-less moot. You need more than 1/4" to get any sort of weld if you use the SMAW process.

J2.1 says the effective through is the depth of the groove for J, U, and 60degree V welds. This is a 45 degree bevel. Depth of groove minus 1/8in.

Can't speak to exactly what RISA Connection is doing without seeing the output. I'm not sure what joint it assumes - you're certain it's not looking at a CJP weld?

 

[YoungGunner]

Ahhh yes, I was not looking at the right angle. Thanks for pointing that out!

For anyone else, I would love to know why the BTC-P4 still says unlimited. That is confusing when it clearly is not.