Elliptical Manway in Ellipsoidal Head
Elliptical Manway in Ellipsoidal Head
(OP)
Hey all,
I am trying to determine which diameter to use in reinforcement calculations for a 12"x16" manway that is inserted into an ellipsoidal head. I know on the shell there is the F factor to take into account the difference between longitudinal and circumferential stresses, but I am not sure how this logic applies to ellipsoidal heads.
Should I use the 12" as the nozzle ID, or 16"?
Thanks!
I am trying to determine which diameter to use in reinforcement calculations for a 12"x16" manway that is inserted into an ellipsoidal head. I know on the shell there is the F factor to take into account the difference between longitudinal and circumferential stresses, but I am not sure how this logic applies to ellipsoidal heads.
Should I use the 12" as the nozzle ID, or 16"?
Thanks!





RE: Elliptical Manway in Ellipsoidal Head
Of course, all this does not apply to nozzles located in heads and the Code states that F=1.0 for all configurations except for integrally reinforced openings in cylinders and cones...not heads.
RE: Elliptical Manway in Ellipsoidal Head
RE: Elliptical Manway in Ellipsoidal Head
Assuming a head as a doubly curved shell of revolution, and that is not a hemisphere (eg: it's semiellipsoidal or torispherical) there will be variations in directional stress in the Nphi and Ntheta directions. But ASME B&PV Code Section VIII Div 1 essentially disregards this for purposes of UG-36 and UG-37.
I think that most people will design elliptical openings in heads per UG-37 using the largest chord opening and F=1.0.