55 gal drum: What transfer pump to use?

[63corvette]

Originally Posted by KRatcliff

I think you are reading it wrong as far as pressurizing goes. I am reading it as adding slightly more pressure than the ambient air pressure which would flow the fuel from one barrel to another. It takes less pressure to move the fuel than what is within the barrel when they "pop" with temperature changes.

It is exactly the inverse of siphoning where you are pulling a vacuum. In both instances you are adding air/oxygen to the original barrel. And you are adding air/oxygen when using a transfer pump.

Even the fuel tank in your car/truck has an air vent that draws air/oxygen into it as the fuel pump removes it during consumption. I think you and Bob are referring to situations that truly pressurize the barrels way beyond what was suggested. YMMV.

No, I understand exactly what you are doing. You are using low pressure to push the fuel out using the same principle as a hyd. jack uses to raise a car.
The issue is adding air/oxygen to the vessel/barrel.
Gasoline has a vapor pressure as all liquids do and will evaporate when it is in an open container. That is the reason for the bungs to be in the barrel when partially full and keep it from going into a vapor. Those vapors fill the void as gasoline is removed.
It is true some air comes in but in very small amounts and air contains only about 19% oxygen. Oxygen is the problem. Much much less than putting an air hose to the barrel. That air amount is what causes the problem and the less liquid in the barrel the greater the danger as that allows more air which in turn is more oxygen.

Like I stated I worked in the oil and gas industry for 40 plus years before retirement and tested and disposed of many barrels over the years. We always used an explosive meter to test the barrels before doing anything with them.
Trust me on this pressurizing a barrel is a bad idea as it is not a pressure vessel and using air instead of an inert gas like nitrogen is a really bad idea.
I do not want to see anyone injured and pressurizing a barrel with air will cause someone to be injured at some point. Maybe not the first or tenth time but at some point it will happen.
Buy a pump and handle gasoline with care as it can be dangerous if not handled properly.
We all pump gas into our tanks daily and most of us do not realize really how dangerous it really is.

I am old and this is my experience.
Rick Cates