Dear All

The joint effeciency RT1 and RT2 is 100% as per asme section VIII div (1). Can any one advice that in which case do we select RT1 and RT2 type.

Best Regards

Ikram Ali Khan

Dear Ikram,

It is the designer who has to select RT type depending upon how he has to manage the vessel economy and safety, either he compromises on the degree of NDE or on thicknesses. Designer has to select the degree of NDE in that case when full RT is neither a Code requirement (see UW-11 carefully) nor by Client specifications.

_________________
Thanks & Regards,
Nasir
Welding Engineer
DESCON Engineering Limited.
Lahore, Pakistan.
Mobile # 0092-336-4145402

Ikram,

RT1 is applicable when the complete Vessel (all butt joints) is RTed.
Please note that this is mandatory for Lethal Service, UB, and materials of thickness above certain limits (UW-11, UCS-57, ...)

RT2 may be used in cases where full RT is not required, but the designer wants 100% efficiency.
If you read the definition of RT2, you find that circumferential joints are only spot RT, still the shell will be calculated 100%, because they are either smls or the long seam is 100%RT.

DK