Close the inlet valve of the receiving container immediately after shutting down the pump so that product
will not drain back into the line.
Dome Unloading. To unload the tank car through the dome, locate the pump at least 50 feet from the
tank car, and ground the pump. Place a drainage tub under the bottom outlet to catch any drainage. Insert
the end of the unloading hose through the tank dome until it almost touches the bottom of the tank. Keep the
hose below the surface of the product until the tank is completely unloaded. Connect the pump discharge
line to the inlet of the receiving container. Place the dome cover over the manhole so that the cover rests
against the hose and allows ample space for venting. Follow pumping procedures described above. When
the tank car is almost empty, manipulate the hose so that all product is drawn from the car. If possible,
remove the bottom outlet cap and drain product from the outlet chamber into the tub.
Follow-Up Procedures. Make sure that the tank car is completely empty. Personnel should gage and
sample contents of the receiving tank, correct volume to 60 degrees Fahrenheit, and record data. Compare
the quantity of product delivered to the receiving tank with quantity taken from the tank car. Report
excessive loss to the proper authority. Allow ample time for any suspended water and sediment to settle in
the receiving tank, drain the water, gage the contents again, and record data. Close the bottom outlet valve.
Remove the unloading hose from the tank car. If a wooden block is used to hold the dome cover open, be
sure that the block does not fall into the tank car. Disconnect the tank car adapter and replace the outlet cap;
tighten the cap with a tank car wrench. Close and lock the dome cover; remove the drainage tub and discard
any product in the tub. If the car has FLAMMABLE placards, remove and replace them with DANGEROUS-
EMPTY placards. Disconnect grounding wire from the tank car; remove derails, if provided; and remove
TANK CAR CONNECTED signs. Release the brakes and remove the car from the transfer area. Notify the
proper authority that the unloaded tank car is ready for removal and is being returned empty, free for load.
Report any defective car to the property authority.
PART N - CLEANING TANK RAIL CARS
The two most common reasons for cleaning tank cars are contamination and change of product. Prior to
beginning cleaning operations, appropriate safety measures must be taken. These include bonding and
grounding the car and placement of safety signs and fire extinguishers. Personnel should clean uncoated
tanks by steaming for one hour. If sludge remains, they should continue steaming until clean. On tank cars
with multiple compartments, ensure that personnel clean one compartment at a time. Allow the tanks to
cool, then check them with a explosimeter. Personnel should remove residual sludge and steam again with
cleaning solvent. Allow the tank to cool then dry with lint-free rags.
Never clean coated tanks with steam. Use air ejector or air eductor to vapor free the tank, check with
explosimeter, then remove sludge. Personnel should scrub the tank with solvent, rinse with warm water and
dry with lint-free rags.
3-16
QM 5098
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