For steel pipe 30″NPS 20 SCH,L= the length of the pipe 12m

a= the tangent length (the straight length to be provided at the end of pipe to facilitate the welding with the main line) 2m(minimum)

r= the bend radius is 40D

so,

My Question is Wat factor i want to consider to calculate the bend angle? Is there any data to calculate this…can anyone plz tell me……