In line water heaters (a.k.a circulation heaters) are ideal for processing fluid, including hazardous liquids, that requires intermediate heating while maintaining a flow rate. Instead of stripping the heat from another source as it would for a heat exchanger, an In line water heater simply transfers the heat generated from electrical power into the target fluid. The main characteristics of the in line heater are for efficient heat transfer, the easiness to install and to maintain, and its high range compatibility with the current standard industrial piping. Applications such as waste oil, steam and water processing can use in line heaters in order to regulate and control the temperature, but also to maintain the fluid viscosity. An improper liquid viscosity could gradually slow down the overall processing time of the production. In addition, the product’s final yield and purity could also be affected by a slight deviation of the viscosity. To avoid this type of problem, a heater inline is used to heat the fluid so that at the proper temperature, the viscosity remains unchanged and at the same time to process the medium at a desirable steady flow rate. To control the liquid flow rate of the heater, the wattage can be manipulated and regulated to obtain the desired temperature (in other words, the flow rate is directly proportional to the temperature/liquid viscosity).


Wattco uses its decades of experience shipping our industrial heaters worldwide. When shipping across borders, Wattco can handle all necessary import, customs and duties responsibilities to ensure that you receive your product on time and on spec. Wattco ships using all mediums upon request including: truck, train, container ship and by air freight when mission critical rush delivery is required.

In line Heater Details

An in line water heater is composed of an immersion heater covered by an anti-corrosion metallic vessel chamber. This casing is mainly used for insulation to prevent heat loss in the circulation system. Heat loss is not only inefficient in terms of energy usage but it would also cause unnecessary operation expenses. A pump unit is used to transport the inlet fluid into the circulation system. The fluid is then circulated and reheated in a closed loop circuit around the immersion heater continuously until the desired temperature (up to 1000°F) is reached. The heating medium will then flow out of the outlet nozzle at a fixed flow rate determined by the temperature control mechanism.

Tools such as the RTDs and digital thermocouples can be used to precisely control the temperature of the heating system. For extra protection, optional components such as moisture resistant or explosion proof housing are available for special applications. Drain valves are also available on the circulation heater to facilitate the procedure with the system maintenance, whereas the leftover fluid or residues (such as water or Calcium) can be easily removed from the equipment. Special mounting options are available for the target application’s mobility requirement. The flange immersion heater inside the circulation unit can be customized by WATTCO™’s manufacturing depending on the chemical and physical properties of the target fluid. Other customization options, such as the equipment orientation (vertical or horizontal) or flange type, are also available to consider for your target application.
There is a large variety of immersion heaters available in the market which can even be tailored to meet specific needs of an oil plant. The offered products can be used in a variety of applications that feature high pressure ranges or are executed in hazardous regions. Generally, whenever an immersion heater is used for heating, it is usually immersed in the solution which has to be heated. As such, the heating elements are often covered by a sheath so that they remain protected.
Inline heaters comprise of heating elements that are mounted in a rounded tube. Often, the flanged heater is thermally insulated by either the side or inline operation so that the efficiency of the heating process can be increased. This is particularly done when a flowing medium has to be heated. Almost all inline heaters use  thermocouple sensors that can be integrated with any control to manage the temperature range. Different applications call for varying options for terminal enclosure, sheath material, flanged connections, and temperature ranges. Several mounting options are also available such as integral mounting utilizing SCRs and remote mounting which uses contractor control panels.
A vessel heater is manufactured as a packaged unit which contains several components such as heating element, chamber, thermostat, sensors, insulated material, brackets for mounting and electrical connections. The efficiency of this heater is high as all heat is produced within the substance or vessel. The operation is fast and executed in a short time. The heat generated is evenly distributed throughout the substance.
Many applications make use of industrial heaters. The most common of these are heating oils, corrosive solutions, water cooled engines, oil sump heaters, process kettles, blending mills, molding dies, steam superheating and preheating purposes such as viscosity pumping and oil delivery to burners.


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  • Options

    2 INCH UP TO 42 INCH

  • ANSI Flange Rating

    150 LBS, 300 LBS, 600, 1500LBS ANSI Non Standard Flanges also available

  • Elements

    Steel, Stainless Steel, Coppor, Titanium, Incoloy®, Inconel

  • Controls

    Thermostatically controlled (0-255F), (55-550F) Digitally Controlled, Thermocouple, RTD

  • Terminal Box Housing

    NEMA 1 Standard Terminal Box, NEMA 4/4X Water Proof Terminal Box NEMA 7 Explosion Proof Terminal Box

  • Industrial Flanged Heater Designed to meet most stringent requirements
  • Sizes from 2 – 14” Stainless Steel, galvanized carbon steel pipe body, 150 LBS up to 1200 LBS Construction
  • Up to 650 kW power requirement
  • 120, 240 and 480V, 575 and 660V, 1 & 3 Phase available
  • NEMA 1 General Purpose, NEMA 4 Moisture Resistant NEMA 7 Explosion Resistant Terminal Enclosures
  • 0.430 inch dia and 0.475” Dia. tubing available using copper, steel, stainless sheath elements
  • With & Without Thermostat, using thermocouples and digital temperature controllers
  • UL, CSA, ASME and Other Third Party Approval, Listing or Certification Available on Many Models
  • Chemical Processing applications requiring inline heaters in a closed or open circuit
  • Petrochemical applications requiring in-line heaters for refineries and oil production
  • Mining industries using inline heaters for water treatment and pressurized applications
  • Food industry using stainless steel inline heaters for sanitation purposes and production
  • Industrial cleaning applications for many companies
  • Military and defence contractors using industrial in-line heaters for various activities
Key Features Benefits
 Flange sizes: up to 14” diameter

  • Titanium, Carbon Steel or Stainless vessels fitted with 150# up to 2000#. psi flanges
  • Insulated seamless vessels available
  • Custom designed units
  • American or European sizes, wattages, and materials are available upon request
  • Vessels can be supplied with Steel, Stainless Steel parts and terminal boxes for heat protection and used in high temperature conditions.
  • Easy installations
  • Skid mounted assembly available
  • Durable and Clean
  • Proven more energy efficient than alternative methods
  • Provides even heat distribution 
  • Greater power available in a smaller heater bundle
  • Provide maximum dielectric strength
  • Reduced vessel heat loss
  • Easy mounting support
  • Suitable with general purpose terminal enclosures, NEMA 7, NEMA 4X NEMA 7, and unsafe or explosion proof locations
  • Compatible with industrial piping and safety standards
  • Digital Control Panels used with Thermocouples to regulate temperature and high limit protection control