Figure 3-6. Testing sears and bolts in tank bottom for leaks

TM 5-5430-209-12

b. Test seam and bolts in the tank working from

b. Push plug through bolt hole, round head down.

the outer edge.

When bottom face of square head bears against the

c. Mix soap solution used for testing in accordance

section, plug is in expanding position.

c. Using two open-end wrenches, one to tighten

with instructions issued with tester.

CAUTION

hex nut to expand plug and the other to keep plug from

Motor starting switch must be in

turning, apply torque slowly to nut. At intervals. as nut

"OFF" position before connecting

is tightened, check plugs' resistance to turning. As

motor to an electric power source

resistance builds, increase turning force on the nut.

d. When plug no longer turns in bolt hole, apply full

outside the tank.

torque to nut until plug completely fills and seals the bolt

d. Measure inside length of the box. Use blue or

hole through the full thickness of sections involved.

red engineering keel and lay out this dimension along

3-5. Testing Seam for Leakage

the seam.

a. The tank bottom must be clean and dry during

e. Position tester on tank bottom. Check starting

testing period. The seam and bolts are tested with a

switch for "OFF" position, and connect extension cord

vacuum seam tester (fig. 3-6) which is incorporated in

(7) to an electric power source outside the tank.

the storage tank erection outfit. Test the seam and bolts

f. Use a sash brush and wipe a heavy coating of

as follows:

soap solution along edge of seam and bolt washers,

between marks on the seam.

g. Set valve (2) to discharge air from box (1) and

start motor-driven pump (4). Position box between

marks on the seam coated with soap solution. A

pressure gage is mounted inside the box. This gage will

indicate atmospheric pressure when pump is started.

When gage indicates an inside vacuum of 3 pounds per

square inch, large soap bubbles will appear at all points

of leakage. Make a mark with crayon on surface of the

area being tested along outside edge of tester at each

point of leakage. Tighten the bolts. Apply additional

soap solution and follow the procedure above until

leakage stops.

CAUTION

Over-tightening of bolts will result in

damage to the strip gasket. Tighten

bolts just enough to stop leakage.

VACUUM BOX

CAUTION

THREE-WAY CONTROL VALVE

Do not move off a tested area with

HOSE

leaks until all points of leakage have

VACUUM PUMP

been stopped.

ELECTRIC MOTOR

WARNING

DOLLY

EXTENSION CORD

If tank is to be used for water

storage, do not apply sealing

compound to tank bottom.

Figure 3-6. Testing sears and bolts in tank bottom for leaks

Section II. ASSEMBLY AND INSTALLATION OF SIDE STAVES

3-6. General

3-7. Side Staves

a. Description. This is a single ring tank with six

Instructions contained in this section, covering

installation of tanks are keyed to the use of hook ladder

staves in the ring. All staves have special sections for

and scaffolds issued with the storage tank erection

pipe connections and a clean out opening. Top and

outfit.

Large boxes or fabricated saw-horses and

bottom flanged edges of staves are called chimes, and

ladders are suitable substitutes for hook ladders and

side edges are called vertical seams. The staves have

scaffolds when erection outfit is not available.

a single row of bolt holes in each seam.

b. Assembling Side Staves.

NOTE

Place all center

Stave assemblies for petroleum and

support ladder components and the manhole dome on

water storage tanks are all the same

bottom of tank prior to installation of last side

except for special fittings

3-6