Fuel tankers, determinging tank size.

Years ago, the station had a stick with markings on it. Some gas haulers carried them with in the hose tube. You'd "dip" the tanks to make sure your load would fit.

 

The "inch to gallon" ratio for a specific tank should be provided to you by your company. Adding ullage means dumping a certain amount, then going to check your veeder-root. Doing it this way increases your chance of a spill. Not good.
Also, most tanks are considered full at 90-95 percent ullage.

 

If the ullage is the same or greater than the amount of product you have, then it won't fit.

Your dispatcher ought to know the tank sizes, but if they don't, then ask the store manager. Also, ask your dispatcher for tank charts. Horizontal tanks do not have a consistent gallons-per-inch (because the diameter is constantly changing), and the mathematical formula is WAY too complicated to do on your calculator or phone.

 

Ullage= room in the tank. I only fill to 90% full.

I dump DEF but same concept.

 

Carry a stick to back you up. Just knowing the tank size will cause you to have a spill. Not all the tanks are the same. You might have a 10,000 gallon tank with all kinds of different readings. To be exact you need to have the make of the tank and a tank chart to make sure. You only should fill the tank to 90% capacity. However, we sold so much gasoline some of the time you bump in the load. But that was way back and we had to stick the tank. I carried in my clip-board several different tank charts and knew the make of the tank in the ground. But nowadays I understand you have to get the reading from the auto tank gauge. I would still stick the tank and look it up. Never had a spill, I guess I was lucky.

 

I've had dispatchers tell me to drop when the gross was over the 90% but the net wasn't. Did it once hit the flapper and never did it again.

 

You know 60° is when gasoline is the same as gross and net. Anything below that and you could have more gallons than you think. We always went after Net.

 

Ullage is the room available in the tank, and the volume is what is currently in the tank. So if ullage is 6,000 gallons and volume is 4,000 gallons it means you have a 10,000 gallon tank with 4,000 gallons of product inside. You only want to fill to 90% of the tank size. So 90% of the 10,000 gallon tank would mean you have 9,000 gallons of usable space. And since there is already 4,000 gallons in the tank, you can safely fit 5,000 gallons. Look at the read out carefully though because some will already have the 90% ullage on the receipt. Some will just show the overall ullage and you have to calculate the 90% ullage yourself.

Also pro tip, if your trying to calculate the 90% ullage, don't just take 90% of the ullage shown on the read out. You will get a wrong number, and it could mess you up. Make sure to figure 90% of the tank size, then subtract the current volume from that.

Hopefully this helps more than it confuses you.