Figure 9-4.Layout of the staves around the tank bottom, 250-barrel capacity tank.
end toward the small end of the deck section. The
flanged side of the deck section acts as a supporting
rafter for the deck section. A bolt retainer angle is
attached to the inside face of each deck section,
flanged to retain the radial seam joint bolts that are
installed near the right edge of each deck section.
SPECIAL SECTIONS. The tank bottom has
one special section, fitted with a blind opening. Four
of the ten staves are special sections. One section is
for a cleanout cover, and the other three sections are
used for pipe connections. The tank deck has three
special sections. Two sections are used for a
combination thief hatch and vent, and one section is
used for a liquid level indicator.
EMERGENCY VENT. An 8-inch vent is
bolted to the top cover of the manhole attached to the
top of the center ladder supports.
The 500-barrel tank (fig. 9-5) has a capacity of
21,000 gallons of liquid and is similar to the 250-
barrel tank, except that the bottom consists of 14
wedge-shaped plates around a one-piece center
section, as shown in figure 9-6. This vertical, bolted
Figure 9-5.500-barrel capacity vertical, bolted steel tank assembled.