By Lindy Lindtveit
In Part II, we pick up our discussion of the new Tigerloop Model TN oil de-aerator introduced in early 2005 by Tigerholm of Sweden and Westwood Products of the U.S. The new Model TN replaces the former Model T60I, which is the original oil de-aerator and which is installed on millions of jobs worldwide. Boasting higher de-aeration capacity, better performance, easier installation and some environmentally friendly features, the new Model TN is sure to maintain Tigerloop’s 25-year leadership position in the field. And, like its predecessor, the new Model TN is UL-listed, which makes it the only UL-approved oil de-aerator available in the United States.
Last time, we learned that ‘bubbles are bad” and discussed the two kinds of bad bubbles: air and gasses. Both cause after-drip and nozzle/combustion head coking problems, as well as burner lockouts, by pushing the oil level in the strainer chamber of the pump down below the inlet to the gear set. And whether bubbles enter the system via a leak or are drawn out of the oil due to high vacuum makes no difference, they still have the same detrimental affect on the system. Therefore, to eliminate the problems you must eliminate the bubbles.
One-pipe vs. two-pipe
Unfortunately, there is no piping arrangement that can, by itself, eliminate the bubbles. One-pipe systems are simple, use less material, prolong filter life by only passing the oil through the filter once and preheat the oil because it moves through the piping slowly. But, they can’t deal with those bad bubbles, either air or gases.
Two-pipe systems can be used on higher lift jobs because they can deal with some of the bubble problems caused by higher vacuum, but they are harder to install, use more material, load up filters much faster, and constantly bring in cold oil to the pump. Moreover, the return line is a pressurized oil line that can be an environmental nightmare if it should develop a leak.
Best of both worlds
What Tigerloop does is combine all the safety and simplicity of the one-pipe system with the added performance of the two-pipe system (Diagram 1.).
From the tank to the Tigerloop it’s one-pipe, with no return line that can leak into the ground. The only oil moving up that inlet line is what’s going out the nozzle so filters last longer and the oil has time to preheat to ambient temperature before reaching the pump.
Between the Tigerloop and the pump it’s two-pipe, with all the self-priming, bubble-handling, high-lift capabilities of a two-pipe system. Long, high-lift jobs are possible because flow rate from the tank is low so vacuum is lower and any bubbles (foam) developed due to vacuum are handled by the Tigerloop. So, while bubbles may be bad, they’re not a problem.
Installation of the new Model TN is even easier than the former model. It has a new detachable mounting bracket that allows the bracket to be mounted first and then the Tigerloop snapped into position. The Tigerloop should be vertically plumb, that is, mounted upright with the vent on top, inlet port on the bottom. That’s important because there are floats inside that must be free to move up and down.
The fusible valve that comes packaged with the Tigerloop should be installed directly into the inlet port on the bottom. If the tank is above the Tigerloop, an oil line safety valve is recommended. A good line filter is a must on all jobs and should be installed between the tank and the Tigerloop. Do not install a filter or anything else that could cause a restriction (i.e. a valve), in either line between the Tigerloop and the pump. This is very important, as any restriction in these lines may cause the pump seal to leak.
Each Tigerloop can handle one burner firing up to 20 gallons per hour. If the burner fires more than 20 gph, two or more Tigerloops can be connected in parallel to supply the required nozzle capacity. On jobs with more than one burner, a single oil line can be used to supply all the burners by using one Tigerloop for each burner. The Tigerloops are ‘teed” into the one line coming from the tank and the normal supply and return lines are run between each individual Tigerloop and it’s corresponding burner. Just remember, each burner requires its own Tigerloop; no sharing Tigerloops.
The actual piping of the Tigerloop is straightforward and easy. Diagram 2 shows a simple one-pipe system, gravity-fed, a great candidate for a Tigerloop. The first step is to mount the Tigerloop in a convenient place close to the burner. Flexible oil lines, available in 24-inch or 36-inch lengths, make the piping easy between the Tigerloop and the pump and are a real asset on swing-out door boilers.
It’s easiest to install the fusible valve and the fittings in the Tigerloop before snapping it into the wall bracket. Once mounted, attaching the inlet line from the tank and the flexible lines to the pump are easy. Just remember to install the by-pass plug in the pump before connecting the lines. When using a Tigerloop, the pump must always be set for two-pipe or the system will not work. Diagram 3 shows the completed piping. The former one-pipe system is now a Tigerloop system.
Diagram 4 shows a simple two-pipe system. It can be converted to a Tigerloop system using the same basic steps outlined above for the one-pipe system. This time, however, you can ignore the step about installing the bypass plug because it’s already installed. Make sure that the old return line that will no longer be used is capped off (sealed) leak tight. It would be a shame to have the next oil delivery’s fast-fill push oil up and out of the old return line creating an ‘environmental incident.” Diagram 5 shows the completed piping of the former two-pipe system.
Perfecting the art…
We have all seen great advances in oilheating equipment in the years since the height of the ‘energy crisis.” Today’s burners are clean and efficient, and with the modern boiler or furnace make for unprecedented comfort and economy. But the technology of oilheating is still developing and the new Tigerloop TN is part of that progress. It is truly another step in perfecting the art.
Lindy Lindtveit is a graduate of Hofstra University and works as a vice president of Westwood Products, South River, N.J. He is also a member of the National Association of Oil Heating Service Managers and a member of the National Oilheat Research Alliance’s Fuels Quality Committee.