Around each burner is a priming pan used to preheat the burner. The resultant heat was used to preheat the air blown into the furnace. Induction heating coils can be used across the width to preheat each belt. Its primary disadvantage is increased electricity consumption to preheat the water in the boiler. Preheat is the first stage of the reflow process. They usually have glowplugs that preheat the combustion chamber to allow starting in cold weather. The burner is then turned off, and the fuel ignited to preheat the burner. In addition, the cooling ware and walls below preheat the incoming air. The flow is then reversed, so that the heated bricks preheat the fuel. The preheat and inter-pass temperatures will depend on the thickness of the material. When the carbon equivalent is between 0.40 and 0.60 weld preheat may be necessary. The outer jets are for preheat flames of oxygen and acetylene. Electronic starters use a different method to preheat the cathodes. It may be used to preheat the feed to a hot-air drier. The exhaust from the turbine then travels forwards through ducts to preheat the incoming air.