Tubular heater is a type of electric heating element with two ends connected. It is usually protected by a metal tube as the outer shell, filled with high-quality electric heating alloy resistance wire and magnesium oxide powder inside. The air inside the tube is discharged through a shrinking machine to ensure that the resistance wire is isolated from the air, and the center position does not shift or touch the tube wall. Double ended heating tubes have the characteristics of simple structure, high mechanical strength, fast heating speed, safety and reliability, easy installation, and long service life.