Defending the Oil Nozzle


Over the years, I have purchased and, like most of the readers, have replaced my fair share of nozzles. I have even represented a nozzle manufacturer for a stint. I would bet that not much has changed when it comes to the number of nozzles riding around in the service vans.

Perhaps you may have well over three boxes of 50 on each van. Some owners, techs and even the supply house employees wonder why there are so many nozzles. When it comes to inventorying them, they are hated by all.

The answer why so many is the same as it was 30 years ago’there are many different applications for every piece of oil fired equipment manufactured, along with specific applications.

What has changed is the range of sizes required in the new units. They have gotten smaller due to the design changes of the equipment, especially on the boiler side. Years back, the smallest nozzle generally was a 1.25 GPH, and now we are seeing more nozzles sold from .50 to .85 GPH, with angles ranging from 45, 60, 70 degrees and several different patterns.

             Service managers have told me that every time they have a service problem, the technician will put on his report that the cause was a bad nozzle, and the question of why is wide open. One quite common answer is ‘I don’t know, but when I replaced it the burner ran.”

I, too, have had some strange experiences over the years. Like the time I did a seasonal burner tune up, replaced the exact nozzle and started the burner, only to notice there was no flame coming from the burner. After checking everything, I pulled the assembly from the 1725 burner and discovered that the orifice in the nozzle was missing, true story!

However, today, I must say that the manufacturers go to great lengths to make sure that the flow rates and the patterns are within a specific range. Generally the flow tolerance of a .50-.85 GPH will have a range of +5%/-3%  and the angle tolerance will be +5 degree to 0 degrees, using oil with a operating viscosity of 35 SSU (Seconds Say bolt Universal), which is about the same as No. 2 fuel.

            Keep in mind there are no moving parts in a nozzle, so they don’t have a wear issue. The main cause is due to oil tank contamination that can cause partial or total blocking of the Tangential Meter Slots along with the orifice. There is the secondary cracking of the oil that can take place when there is too much heat on the nozzle that causes miniscule carbon particles to be released from the oil and enters into the nozzle, again causing a burner failure.

Rather than blaming the nozzle, I would suggest that you think about double oil filtration. However if the oil tank is as old as the original 30-40 year old  boiler or furnace being replaced, replace the tank at the same time.

 However, if the owner doesn’t want to make the change and you want to reduce nozzle and service call issues, I suggest completely remove the cartridge from the typical B-4 or 1A25 at the tank. You will now have created sludge – pot to collect the larger portions of sludge. Now install another complete filter after the sludge pot to support the filtration needed to help protect the nozzle.

Also, make sure that when replacing a nozzle where you have questioned its performance, that you have a current Burner Manufacturer’s OEM guide and follow it. So as you can see, I’m somewhat defending the nozzle!

            I have been asked about an adjustable nozzle, nice thought, but I don’t see that happening in my time!

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