Over the years I’ve written plenty of articles on pumps, vacuum and why things don’t always go as planned. I’ve begged the retail oil industry to use more fuel additives and treat the oil year round and not wait until a tank is frozen in the middle of the winter. It’s not just the frozen tank that bothers me, it’s the very irate customer you have.
I’ve also pleaded for the use of pressure and vacuum gauges and even just to follow simple rules of thumb when calculating the design of fuel systems and to use them while troubleshooting. I just don’t preach this stuff, I really believe in it. If it works I love it, if not, at least I tried it. Try things ‘ it only takes one new idea and keep an open mind!
Well, as we all know this was a very crazy winter and the cold never did show up. That was good because many problem jobs stayed quiet, but what will next year bring? I was just on the phone trying to get someone to understand that at over 10 inches of vacuum there are better ways to get oil to a pump in cold weather than a two-pipe system. You can use all of the tricks and gadgets you want, but I hate living with a recurring problem, a curse, if you will. You can keep trying to use your two-pipe systems, two-stage burner pumps, and everything else, but when you have to move oil, you just can’t beat a pump and pressure, FACT!
Way back when I was just an apprentice, I got hooked on booster pumps. I got hooked by reading an article from the old NOFI group, and it was an eye opener ‘ the proof is it really stayed with me. Here’s the basis of the story: You have a 10,000 gallon oil storage tank at just below ground level. The utility room is 225 feet aboveground level and your peak firing rate is 115 gph that is consumed by two boilers and a water heater. That’s right, 115 gallons per hour and this is all contained in a 32 story building called the Southdale Tower in Edina, Minnesota. In a brief search of the Internet, I couldn’t find out if the building is still there, but I did find out that Edina is the home of the first covered shopping mall in the United States, cool!
So, the engineers needed to pump the oil up 225 feet and deliver 115 gallons of No. 2 oil to the equipment, so did they use a two-pipe system? Oh sure, did they use anything else? Yeah, they used properly sized lines and a couple of boosters. They really only needed one, but with a big building like this you build in a backup for the ‘what ifs.’ Figure 1 is my re-drawn version of the piping system that was laid out by the former Heating Division of Sta-Rite Industries, Inc., also known to many of us as Webster pumps, Figure 2.
Let’s look at a few key items. First is the oil supply tank at the top of the building, which is nothing more than a 10 foot long piece of six inch pipe. Using the following table you can calculate just how much that pipe holds.
Schedule 40 Pipe
Nom. Dia. / Inches
Gallons per Foot
Nom. Dia. / Inches
Gallons per Foot
Notice the valve located at the top of the system? That’s an anti-syphon valve, Figure 3, not an osv valve. There are four pressure regulating valves on the job. These are required to maintain the correct pressure between all points of the system from getting too high and damaging anything like the pump seals. Remember, from where the pumps are located, they have to push up 225 feet!
The funny part is no where do they tell us what the lift was for the boost pumps, but I’ll take an educated guess that the total lift from the bottom of the suction lines to the inlet of the boosters was no more than 10 feet. The pipes leading to the manifold at the top should be at least ¾ inch pipe and the return should be one pipe size larger.
With today’s technology you could probably redesign this a bit differently, but then again you can’t fix something that isn’t broken. When you study this design you’ll see why I became so hooked on booster pumps and why I truly believe: ‘If you want to move oil, you must use pressure, vacuum just isn’t going to cut it. You can push oil all the way to China using pressure, but you’re not going to do it with vacuum.”
By the way, did you figure out how much oil is in that manifold? You should have come up with 13.5 gallons.
That was a big job; let’s look at a smaller one. As many of you know I’m absolutely convinced that there is probably nothing needed on any burner running under 20 gph other than a single-stage pump and a single-pipe system. Most people think that I’m nuts, but most of you live with the problems that two-stage pumps and two-pipe systems create, not me. I also think that the retail oil industry may have and is still needlessly losing a lot of accounts over these two items. But again, someone has suffered the losses other than me.
Two-stage pumps are considered a panacea by many along with two-pipe systems and check valves, another unnecessary curse. The truth is that when you take oil to over 10 inches of vacuum, nasty things start to happen. Add in sulfur; a solid by nature, whose content has been lowered, a red water soluble dye and a few bushes and twigs and plants in the form of biofuel and you have a mixture that may not behave as you planned. When you take oil over 10 inches, you begin to rip apart the oil and essentially begin to aerate it. The problem is that fuel pumps were meant to pump oil, not air or hydrogen, which is what happens when you begin to separate oil under vacuum.
Figure 4 and Figure 5 are pictures you’ve seen before, either in my seminars or articles. They show, in Figure 4, oil at 10 inches of vacuum and at 20 inches of vacuum, Figure 5. In Figure 6 you can see the oil doesn’t even look like it’s moving, has no bubbles and foam in it, and the pump is just merrily pumping away. At zero vacuum a pump may be in operation, but it’s not really working. To make a pump work, you need to put it under vacuum. One of my favorite quotes is: ‘Under pressure you can pump oil to China, but with vacuum you are very limited.” That’s one of my own and something I’ve been saying since the 1970s. Pressure gauges can be purchased with scales as high as 10,000 psi, but vacuum only goes to 30 inches, because vacuum is absolute at 29.99999 inches, period. Is any of this boring to you? See ya soon!
*George Lanthier is the owner of Firedragon Academy, a teaching, publishing and consulting firm. He is the author of over 40 books and manuals on gas and oil heating and HVAC subjects. He is a CETP, NORA, NATE and PMEF Proctor and can be reached at 608 Moose Hill Road, Leicester, MA 01524. His phone is 508-421-3490 and his website can be found at www.FiredragonEnt.com
Oil Booster Pumps, Revisited – Part 2
by George Lanthier*
Let’s continue with our look at oil booster pumps. If you haven’t seen one yet there’s a new booster out there, Figure 1 and Figure 2. This is a brand new boost pump from Suntec called the Bx-xxxxCM. You’ll replace all the little x’s with the pump and pressure ranges you need and get from Table 1.
# Waste Oil Unit for replacement of exact model only!