ANSI rated flange, usually made of steel, is ideally suited for industrial process heating. However other materials such as stainless steel are also used. The sheath materials used in heating elements include: steel, stainless steel, copper, and INCOLOY.
For process temperature control, WATTCO provides a thermowell–located among the heating elements bundle–with a sensing bulb inside. Flange heaters are installed on a tank or vessel wall using a companion flange.
The primary use of flanged immersion heaters is in process heating, specifically for heating gas and liquids in storage tanks, oil containers, food process equipment, and cleaning and rinsing tanks. The direct immersion method is an efficient process.
The flanged heater is usually installed are by bolting it to a matching flange welded to the tank wall or nozzle. The maximum sheath temperature of the element material is a very important parameter. It depends on: 1) viscosity 2) specific density and 3) corrosive properties of the heated medium 4) contaminants present, if any, in the heated medium 5) corrosion resistive properties of the sheath material. Figure 1: Typical watt density for flanged heaters.
The thermowell is comprised of a sensing bulb that is capable of transmitting the temperature readings to a digital temperature controller to keep the temperature to a desired setting. A thermocouple is placed inside the thermowell for an electronic-based mechanism of temperature control. The thermocouple is factory installed and is connected to a temperature controller.