1.Sulfur dioxide gas can only be used during normal operation of the tempering furnace. Pump in sulfur dioxide gas for approximately 10-15 minutes when the tempering furnace starts to heat the glass.

2. Use sulfur dioxide only if it’s necessary. It is used mostly when the tempering furnace starts to process glass after cleaning. Sulfur dioxide gas should be used as little as possible since excessive use will make the tempered glass blueish. Sulfur dioxide gas will also leave brown spots on the surface of ceramic rollers, possibly causing spot marks on the tempered glass. 

3. Generally, the flow speed of sulfur dioxide gas is 1-4 cubic centimeters per minute, with a maximum of no more than 7 cubic centimeters per minute; the pressure of sulfur dioxide gas should be kept at approximately 50 kPa.   

4. Do not use the sulfur dioxide gas before the glass tempering furnace reaches the tempering temperature.