2. Mark this center peg at a point 6 inches from the
top) and drive it down in the grade to this mark.
3. Use a wooden straightedge with a carpenters
The 100-barrel tank shown in figure 9-1 is the
level attached to set grade stakes about 10 feet apart.
smallest bolted steel tank. It has a holding capacity of
Note that, set in this manner, they will protrude 6 inches
4,200 gallons of liquid and is made up of preformed
and punched metal sections, fastened together with
above the earthen grade.
l/2-inch-diameter bolts. The tank bottom (fig. 9-2)
4. Distribute sand over the whole grade, using
consists of two semicircular halves, bolted together at
shovels and rakes. When the sand just covers the top of
a lap joint along the center of the tank bottom. This
each of the stakes and the center peg, the proper level
vertical, bolted steel tank has a 9 foot 2 3/4-inch-inside
has been reached.
diameter and is 8 feet 1/2 inch high at the sidewall.
5. Drive the stakes and the center peg all the way
SIDE STAVES. The side staves consist of six
down into the earth under the sand. When the tank is
curved, vertical sections, arranged in a single ring. The
filled, the sand will compact, and if the stakes are not
staves are chimed (flanged) at the top and bottom of
driven down, they may cause leaks. Mark the position
each section with the left end of each chime offset so
of the center peg with a temporary pin so that you will
the vertical seams overlap. The bottom chime bolt
be able to position the center of the tank bottom later.
holes are patterned to match the outer edge bolt holes
6. To make the surface smooth, use a sweep with
a carpenters level attached. Pin the sweep to the center
peg and drag it over the sand, filling in any hollows and
smoothing out humps. The sand pad should be at least
4 inches thick and should have a crown of about 1 inch
in 10 feet of tank radius; however, the crown should not
exceed 6 inches.
When a foundation is properly prepared, many
unnecessary problems do not occur during
construction of the tank. Just imagine the problems
that might occur, both in erection and in subsequent
maintenance of a tank, if the foundation were to settle
unevenly, throwing the steel plates on one side of the
tank slightly out of line. Remember that the walls of
the tankconsisting merely of steel plates bolted
together-must act as bearing walls to support the
roof. So, make sure you have a good foundation before
starting to assemble a tank.
in the tank bottom. The vertical seams have one row
of bolt holes.
Figure 9-1.100-barrel capacity, vertical, bolted steel tank.
BOLTED STEEL TANK ASSEMBLIES
Tanks are assembled by sections, consisting of
pieces of various sizes and shapes that combine to
form cylindrical structures. Among the most common
are the bolted steel tanks, having a capacity of 100,
250, or 500 barrels of liquid Many tank sections serve
the same function regardless of tank capacity.
However, the number of sections used in each
assembly will vary according to capacity. The
procedures for assembling and erecting these tanks are
Figure 9-2.Tank bottom.