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Care and Handling Tips

VERY IMPORTANT!
Before installing a new nozzle, it is very important to flush the nozzle line and adapter with at least a pint of oil pumped through it to remove sludge and dirt. Or you can blow out the line with compressed air if it's available. Failure to do this has been the reason for numerous callbacks for plugged nozzles.

Until installation, keep nozzles in their original containers and preferably in a suitable box or rack. They should not be permitted to roll around in a drawer or toolbox, or carried loose in pockets. On service calls, they should be kept in a clean nozzle box.

Handle the nozzle carefully after removing from its individual container. Pick it up by the hex flats and by all means avoid touching the filter or strainer with greasy hands. This can force foreign material into the nozzle where it can finally work its way into the slots. The possibility for problems is even greater with nozzles of lower flow rates since they have smaller slots...easier to clog.

Nozzles should always be handled with clean tools... again to reduce the possibility of contamination. To properly service a nozzle and check its performance, it's recommended that you use a pressure gauge, vacuum gauge, a nozzle changer and flame inspection mirror.

Be sure the strainer or filter is in place on the nozzle before installation. Do not disassemble the nozzle before installing it because great care has been taken to make sure the nozzle is absolutely clean on the delivery.

The nozzle orifice is polished to a glasslike finish. Don't ruin it with a wire or pin, or by bumping it with a wrench. This can cause streaks in the spray.

Don't blow into the nozzle. While this may seem to be the handiest and quickest way to "clean" a nozzle, you run the risk of contaminating it instead.

A nozzle can become overheated due to back pressure in the combustion chamber. This results in coke and sludge formation both inside and outside of the nozzle. To correct this problem, set the over fire draft for at least .02 inches of water column or follow furnace or boiler manufacturer's specifications.

On a conventional installation, be sure the end of the burner tube is flush or slightly set back with the inside wall of the combustion chamber to prevent the nozzle from becoming overheated. Follow manufacturer's specifications when available.

Make sure the fuel tank is clean. Water and sludge in the tank can clog lines, filter or nozzles.

Be sure the supply line filter (between tank and burner) is adequate for the size of nozzle used.
It will remove many of the small particles which may be present in the fuel oil or formed in the tank. Filtration is particularly recommended for burners using small nozzles. The filtering element should be replaced at each summer cleanup and the line flushed out with oil. The Delavan line filter should also be replaced annually.

Nozzle Cleaning - A quality nozzle should last through a normal heating season provided that an excellent to superior grade filtration system is used. A Delavan nozzle is a fixed precision metering device with no moving parts. When not overheated, there have been cases where a nozzle has worked several heating seasons trouble free. However, most service organizations have shown that the best, most economical results can be obtained by replacing nozzles annually. To clean a nozzle properly is a painstaking, time-consuming job. And in the lower flow rates, it's practically impossible to see whether the orifice and distributor slots are thoroughly clean without the aid of a microscope. Also, disassembly of, or tampering with the nozzle will void the manufacturer's warranty. In the long run, you will save your time and the customer's money by a program of nozzle replacement.