5.3　Bends and Elbows

5.3.1　The strength of bends and elbows shall meet the requirements in 6.3.1 of this code.

5.3.2　For main steam，reheat steam，and high pressure feedwater piping，bends with a relatively large bending radius（3-5 times the outer diameter of pipe）should be used.

5.3.3　For piping with a design pressure of 6.3 MPa or above or the piping with a design temperature of 400℃and above，the elbows，if used，should be provided with straight pipe section.

5.3.4　For cold reheat steam piping which are selected to be electric-fusion-welded steel pipes，the elbows should be fabricated with electric-fusion-welded steel pipe of the same quality using hot processing.