Webster's model SC series boiler burner is engineered specifically to operate with low emissions without the cost and expense of external flue gas recirculation piping or the maintenance issues associated with surface combustion technology. The SC series burner combines the reliable and rugged burner technology Webster is known for with a new, patented staged combustion firing head. The SC burner can achieve 30 ppm NOx levels while maintaining very low O2 levels, which results in excellent efficiency, and can achieve as low as 9 ppm NOx levels with an increase in O2. The SC burner is available for Scotch-Marine, firetube, watertube, flextube, firebox, and other heaters and vessel types. It can fire natural or LP gas or No. 2 oil. It has lower excess air requirements for efficient operation.