5
FIGURE 3-2
The pressure-relief device or regulated air source must be
rated at a maximum of 6 psig [4 psig for a 12-foot-diameter
tank] to reduce the risk of overpressurizing the tank.
3.2. TESTING A SINGLE-WALL TANK
3.2.1. Remove all temporary service-fitting plugs.
3.2.2. Redope fittings and install plugs in all openings, except
one service fitting (needed for the test manifold).
Follow
instructions in Point 3.1.5.
3.2.3. Install the test manifold in the open service fitting. Connect
the pressure source to the test manifold.
(See FIGURE 3-3.)
FIGURE 3-3
3.2.4. Pressurize the tank to 5 psig [3 psig for a 12-foot-diameter
tank]. Allow the pressure to stabilize by adding or removing air
as necessary.
3.2.5. Close the air-supply valve on the test manifold. Disconnect
the air-supply line.
3.2.6. Soap the entire exterior of the tank, checking for leaks.
(Follow instructions in Points 3.1.6. through 3.1.8.,
including
Warnings following 3.1.8.)Watch for active air bubbles, which
indicate a leak. Pay special attention to fittings and manways.
3.2.7. Monitor the pressure for one hour.
Pressure-Relief Device
Air-Supply Valve
Air-Supply
Gauge
Service Fitting
From Air Supply
Max
5 psig
While moving or lifting the tank, do not position any part of
your body underneath the tank. This could result in death
or serious injury.
Do not lift or hoist a tank under pressure. This could result
in death or serious injury.
3.1.9. Refer to the appropriate section below for instructions for
the following situations:
3.1.9.1. For testing a single-wall tank,
see SECTION 3.2
.
3.1.9.2. For testing a double-wall tank with a dry interstitial
space,
see SECTION 3.3.
3.1.9.3. For testing a double-wall tank with a wet interstitial
space,
see SECTION 3.4
.
3.1.9.4. For testing a single-wall multicompartment tank with a
single-wall bulkhead,
see SECTION 3.5.
3.1.9.5. For testing a single-wall multicompartment tank with a
double-wall bulkhead(s),
see SECTION 3.6.
3.1.9.6. For testing a double-wall multicompartment tank with a
dry interstitial space,
see SECTION 3.7.
3.1.9.7. For testing a double-wall multicompartment tank with a
wet interstitial space,
see SECTION 3.8.
3.1.10. If damage is detected, do not attempt repairs. Contact
the UST coordinator at the Xerxes plant nearest you. Telephone
and fax numbers are found on the back cover of this manual.
3.1.11. After installation and before backfilling to grade, testing
must be repeated to verify that no damage has occurred during
installation.
When the tank is under pressure, the manways and/or
fittings may dislodge, or the tank could rupture and result
in death or serious injury. Before beginning the test, notify
all people on the test site to remain in a safe location.
ALWAYS ATTEND TO THE TANK DURING THE TEST. Stand
clear of manways, fittings and tank ends during the test.
The maximum test pressure is 5 psig [3 psig for a 12-foot-
diameter tank]. Position the pressure gauge so that the
pressure readings can be clearly read at all times. See
FIGURE 3-2.
