g. Installing Last Deck Section.
plate (1, fig. 8-55) in that order. Install nut on bolt and
(1) Raise last deck section (3, fig. 8-55) before
(6) Remove nuts temporarily installed on all
the next-to-last section (4) is installed.
bolts in the deck lap seams. Install steel recessed
(2) Install two wedge gaskets (5) in the deck
washer, cup side down, and nut on all bolts (5, fig. 8-
opening on top chime of third ring. Follow procedure
55), except on bolts in the top chime of the third ring.
described in paragraph 8-4d (1) and shown in figure 8-
Make sure rounded head of nut is against the washer.
Tighten the bolts.
(3) Install last section (3, fig. 8-55) by placing its
h. Install Center Deck Plate.
lap seams over the lap seams of adjacent sections (2
(1) Insert 1/2-by 1 1/4-inch bolts (6, fig. 8-55)
and 4). The large end fits over the bolts in the top
through small end of sections forming the outer bolt
chime of the third ring. If the last section does not fit the
circle of center deck plates.
adjacent sections and the inner support properly, raise
(2) Apply strip gasket (7) to bolts (6). Install
or lower the center support, c above, until the proper fit
wedge gasket (5) under strip gasket (7) at lap seam of
every deck section.
(4) Remove boom (3, fig. 8-52) and lower to
(3) Place center deck plate (1, fig. 8-56), over
ground. Disassemble the boom and return the items to
bolts (6, fig. 8-55). Install steel recessed washer, cup
the storage tank erection outfit.
side down, and nut on each bolt protruding through the
(5) Install step plate (1, fig. 8-55) at top of top
plate. Make sure rounded head of nut is against
center support (1, fig. 8-44). Aline bolt holes and insert
washer. Tighten all bolts.
a 1-by 9-inch bolt through the support (1) and
Section V. ASSEMBLY AND INSTALLATION OF TANK ACCESSORIES
8-19. Manhole Dome
a. General. The manhole dome consists of one-
(1) Place manhole cover gasket (7, fig. 8-56)
over the cover flange of dome (6). Insert bolt (8)
piece, flanged, tubular, steel sheet. It is attached to the
through all bolt holes in the dome flange and gasket (7)
hatch in the center deck plate. The deck flange has 30
in that order. The gasket will hold the bolts in place.
bolt holes. The cover, or vent flange, has 28 bolt holes.
(2) Install the flange of vent (9) over bolts (8).
Install steel recessed washers, cup side down, and nuts
(1) Place deck gasket (5, fig. 8-56) over the
on each bolt (2).
hatch boltholes in center deck plates (1). Insert bolts (2)
through all bolt holes in the plates (1) and gasket (5) in
8-21. Access Ladder
that order. The gasket will hold the bolts in place.
a. General. The access ladder consists of three
(2) Install wedge gasket (4) under the gasket (5)
at the lap seam of the plates (1).
bolted, steel angle rails. The top section of the ladder is
(3) Install the 30-bolt hole flange of dome (61
attached to the deck by two fabricated, steel handrails.
over bolts (2). Install a steel recessed washer, cup side
Bolted, steel angle braces support the ladder at the
down, and a nut, rounded head down, on each bolt (2)
remaining stave chimes.
b. Assembling Bottom Section.
protruding through the flange of dome (6).
(1) Place two ladder rails (1 and 2, fig. 8-57)
8-20. Emergency Vent
with similar bolting legs facing each other, on top of
a. General. The vent is a one-piece, round, cast
several pieces of blocking sufficiently long to support
both rails spaced wide enough apart to install a ladder
steel body fitted with a lifting handle and hinge lugs.
The vent comes attached to the flanged body by hinges,
and seals the deck opening.