Remove and disassemble wingnuts (2), Iockwashers (3), hooks (4), hook bolts (5), and gasket (6).
Disassemble latch assembly by removing hinge bolts and nuts (7) closing cam (8), and locking
Remove nut (10), washer (11), bolt (12), washer (13), two washers (14), and spacer (15) and
remove closing cam (8). Remove Fuse Plug, gasket and nut (16). Remove Vent Assembly (17). Remove
metal gasket retainer (18) and rubber gasket (19).
c. Cleaning and Inspection.
Drycleaning solvent, P-D.680, used to clean parts is potentially dangerous
to personnel and property. Avoid repeated and prolonged skin contact. Do
not use near open flame or excessive heat. Flash point of solvent is 100
degrees F -138 degrees F (38 degrees C-59 degrees C).
(1) Clean parts with dry cleaning solvent (item 1, Appendix E) and dry thoroughly.
(2) Inspect parts for breaks, cracks, damaged threads, and other defects.
(3) Inspect gasket.
(4) Replace defective parts.
(1) Position cover gasket (6), and install manhole cover (1) on tank,
(2) Space hook assemblies around inner perimeter of manhole cover and tighten wingnuts (2).
(3) Lower hinge (8) over cover and lock with release cam (9).
The manhole cover assembly (figure 4-16) is provided with a vent assembly located in the cover which
vents at approximately 0.5 psi (0.0352 kg/sq cm) of internal pressure. It is also equipped with fuse plug
which will melt at 170 degrees F to 190 degrees F (77 degrees C to 88 degrees C).