Fabricator use different methods, a good approximation can be given by For plate thickness less than 25 mm / 1.0 inch Blank Diameter = D + (D/42) + (2*S.F)+ ((2/3) * Kr) For plate thickness equal or more than 25 mm / 1.0 inch Blank Diameter = D + (D/42) + (2*S.F) + ((2/3) * Kr)+ thk where, D = Outside Diameter of Ellipsoidal HeadS.F. = Straight FaceKr = 0.17*D = Knuckle Radiusthk = Thickness of Head
have you vedio for ; UG-34 UNSTAYED FLAT HEADS AND COVERS ASME VIII Div 1 ?
What is the blank diameter we should use for elliptical head fabrication
ID+2 TIMES THICKNESS+2 TIMES SF+10% Of ID
Fabricator use different methods, a good approximation can be given by
For plate thickness less than 25 mm / 1.0 inch
Blank Diameter = D + (D/42) + (2*S.F)+ ((2/3) * Kr)
For plate thickness equal or more than 25 mm / 1.0 inch
Blank Diameter = D + (D/42) + (2*S.F) + ((2/3) * Kr)+ thk
where,
D = Outside Diameter of Ellipsoidal HeadS.F. = Straight FaceKr = 0.17*D = Knuckle Radiusthk = Thickness of Head
ID+2 TIMES THICKNESS+2 TIMES SF+10% Of ID