Boiler Codes - ASME - Maximum opening diameter Shells and Headers

ASME - Maximum opening diameter Shells and Headers

Maximum opening diameter Shells and Headers

MKS: Diameter/Thickness- mm, Pressure/Stress- kg/cm2

SI: Diameter/Thickness- mm, Pressure/Stress- Mpa

FPS: Diameter/Thickness- in, Pressure/Stress- psi

Shell/Drum OD, D:

Shell Thickness, t:

Shell Design Pressure, P:

kg/cm2

Stress Valus, S:

kg/cm2

Max Dia of Opening, d:

Smaller of ID/4 & 60mm

Larger of the above

OPENINGS IN SHELLS, HEADERS AND DISHED HEADS

D = the outside diameter of the shell, header, or dished head containing the opening, in. (mm)
d = diameter of a finished opening, in. (mm)
dmax. = the maximum permissible finished opening diameter for an uncompensated opening, in. (mm)
K = PD/1.82St (where K shall not exceed 0.990)
P = the maximum allowable working pressure
S = the maximum allowable stress value, taken from Tables 1A and 1B of Section II, Part D t = the nominal thickness of the head, shell, or header, in. (mm)