User Guide

4
Nozzle Selection
To match a nozzle to a burner takes field-service experience, trial-
and-error, or a good foundation of understanding angles, rates
and patterns.
Nozzle Ratings and Testing
To insure consistent quality, every Delavan
nozzle is tested for flow rate and spray angle on
modern, high instrumented test stands. Spray
quality is observed during testing for
uniformity, balance and flutter.
Delavan Nozzles
Test oil is mixed to nominal no. 2 oil
specifications. The viscosity is
maintained within:1±.04 centistokes
(.03 SSU), gravity to a total spread of
11/2° APl and temperature at 80°F
±2° F. Test pressure is set at 100 psi.
These conditions are continuously
monitored and instrument accuracy is maintained within ±.5% or
better. Nozzle testing is conducted in an air-conditioned, controlled
environment, with a temperature variation of 4° F maximum.
Nozzle Types
Type A
Hollow Cone
(Creates stable flame
at low flows)
Figure 3
Hollow Cone Nozzle (Type A)
Hollow cone nozzles can be used in burners with a hollow air
pattern and also for use in small burners (those firing 1.00 GPH
and under), regardless of air pattern. Hollow cone nozzles
generally have more stable spray angles and patterns under
adverse conditions than solid cone nozzles of the same flow rate.
This is an important advantage in fractional gallonage nozzles
where high viscosity fuel may cause a reduction in spray angle
and an increase in droplet size.
Type A nozzles produce a spray which delivers fine droplets
outside the periphery of the main spray cone. These fine droplets
greatly enhance ignition and create a stable flame for use with
flame retention burners.
For Type A Del-O-Flo
®
low flow nozzles (see page 5).
Nozzle Vial
Type Color
A Red
Del-O-Flo A Black
B Royal Blue
Del-O-Flo B Gold
W Green