MIL-T-15301D(SHIPS)
Code, section VIII, in which half the minor axis (inside depth of the head minus the skirt) equals one- "
fourth of. the inside diameter of the head skirt. All heads shall have a skirt prepared for butt welding
to the shell. The minimum skirt length shall be three times the head thickness or 1-1/2 inches, which-
ever is less.
Sizes, locations and details of piping connections shall be as specified
3.3.6 Piping connections.
(see 6.1).
3.3.6.1 Class 1 tanks. For class 1 tanks where connecting piping is nonferrous, piping connections
shall be 6 inch long steel pipe nipples, type E, in accordance with MIL-T-20157.
3.3.6.2 Class 2 tanks. "For class 2 tanks where connecting piping is nonferrous, studding pads shall
be in accordance with figure 1, except that drilling and facing shall be in accordance with MIL-F-20042.
3.3.6.3 Studding pads in accordance with figure 1 shall be used where ferrous connecting piping
incorporates steel flanges in accordance with, USAS B16.5.
Figure 1.
Detail section of studding pads.
3.3.7 Handhole. Unless otherwise specified (see 6.1), each head shall have a 4 by 6-inch handhole
flued inward as shown on figure 2. The minimum depth of flange of the flued opening shall be three times
the required head thickness. The handhole fluing radius shall be 7/8-inch for heads 1-1/8 inches thick
and under. For thicker heads, the radius shall be increased proportionately,
Figure 2.
Handhole cover.
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