BY GEORGE LANTHIER

As I write this new article I think of old friends and teachers along the way heading towards retirement . Been very fortunate to have learned from so many and been able to pass that knowledge forward . For me , that ’ s what education is all about .

Most of this material is taken from our textbook , FUEL SYSTEMS HANDBOOK , From the Oil Tank to the Pump and this article is going to be about a couple of pump tricks learned from old friends .

I ’ m quite sure that if you ’ re reading this you have run into the infamous problem of what to do when you run into a situation where you have one oil line coming from a tank and have to get two pumps to feed off of it . In most cases the best solution is to run two lines , period .

Over the years I ’ ve probably had hundreds of guys ask me about this problem and to be honest I ’ ve tried every trick in the book to make this problem go away . Believe me , I ’ ve tried solenoid valves , priority relays , oil safety valves , check valves , floor level tees , you name it and the ole Firedragon has given it a shot . Sometimes the best teacher is failure . The only way I ’ ve finally got it to work is to run two lines from the tank to each burner and using these two methods which amount to a pseudo ( simulated ) two-pipe system .

These “ tricks ” were taught to me by one of my teachers and mentors and one smart pump guru , Lindy Lindveit .

When I first learned this from Lindy , he was with Sid Harvey ’ s and he kept teaching it after he went to Westwood , now part of Beckett , the simple reason , they work ! Another pump guru back in the day was Paul Kelley . He did a lot of teaching for

Figure 1

Sid ’ s and NEFI in Springfield , MA , and also taught the two ways we ’ re going to look at .

The first tip is for two pumps at different heights . This can get nasty simply for that reason , the height disparity . Keep in mind that height is equal to lift for a pump . That ’ s the rub . Let ’ s review what I feel are the most important two things to remember when troubleshooting pumps and pump delivery problems : gravity , and lift .

In Figure 1 we see a pump and a tank . Note the fuel line running from the tank and into the pump at the middle of the pump , that ’ s a reference to the shaft . The shaft is important because it ’ s going to act as the baseline and our point of reference for this discussion . The simple thing to remember is “ flooded suction ” versus “ lift

Figure 2

suction ” also known as gravity versus lift .

Please note that all of these diagrams are not to scale , and we have not shown valves , filters and other items that might be required by ‘ good industry practice ’

Figure 3

and Code . We just defined ‘ gravity ’ as ‘ flooded suction ’ and a ‘ lift ’ or vacuum job as ‘ lift suction ’. Gravity is the most beautiful of all pump piping conditions . Simply because with most or all of the oil above the pump shaft , oil will always make its way to the pump with little or no effort . What makes me just shake my head is how some people go out of their way to screw up a beautiful thing and make it a disaster . Number one

Figure 4

way to do it ? A check valve .

Look at Figure 1 again . Knowing that our pump shaft is our point-of-reference between where the oil goes from a gravity to a lift condition , why does the oil still flow from the tank when we have a tank that is less than half full ? It ’ s simply because of the static pressure caused by the weight of the oil in the tank . Fueloil ( biofuel ) now weighs about 7.8 pounds to 8.0 pounds per gallon depending on the other things that may be in it like the ratio of the biofuel product . With a full tank of about 260 gallons your static weight is approximately 2020 pounds . At a half tank of fuel ( about 130 gallons ) your static weight is about 1070 pounds and that static weight is pressing on everything from the tank to your pump strainer . The oil wants to get out so your pump at this point is still operating since the oil is literally being delivered to it through ‘ static pressure ’. But what happens when all the oil ( and weight ) is below the pump shaft , pure absolute lift , Figure 2 , and now your pump is not only operating , it ’ s working !

A couple more of my teachers were Bill Mitchell and Pete Fee of Suntec ( formerly Sundstrand ). Bill and Pete used to explain

34 FEBRUARY 2023 | FUEL OIL NEWS | www . fueloilnews . com