MANHOLES, MUDHOLES, ETC.
Compensating Rings and Frames for Openings in Shells
||Compensating rings and frames
for openings in shells shall be of wrought or cast steel.
The compensation provided shall preferably be flanged
frames, which shall be fitted in all cases where the shell
plate exceeds 9/16 inch thick. Flanged frames shall be
weldless and shall be flanged or pressed to provide a
flat jointing surface for the cover.
||All compensating rings and
frames shall be formed to bed closely to the surfaces
to be connected. Where attached to cylindrical shells
and are 12 inches x 9 inches or larger they shall be atleast
double riveted. All caulking edges shall be machined or
machine gas cut.
||The flat jointing surfaces
of all flanged or pressed frames and all doors or covers
shall be machined.