Hello

Connections of a piping on another involve discontinuities (penetration in the collector, sharp angles of connection, etc…) and local intensifications of constraints generate. The codes define coefficients of intensifications of constraints for the reports/ratios of collecting diameter/connects lower than 2, but nothing for the higher reports/ratios.

Do you have any idea about this??
I search any Theory or study

Thanks

Actually, the SIFs in the piping codes are based on tests performed on 4x4 Std fittings, so the D/d ratio was 1.0

Additional work has been done in this field and has been published in various WRC (Welding Research Council) bulletins. Here is the link to the WRC web site .