Process Steam Circulation Heater: Materials & Design

CirculaSteam injection heaterstion Heaters for Process Applications: Steam

Steam is used in various process heating applications, both for home and commercial situations. Yet, circulation heaters for processing steam are primarily found in the industrial heating industry. A process steam circulation heater is used in applications where steam needs to be heated to a finely controlled set-point. 

This is achieved by providing indirect heating to various types of steam with a flanged immersion heater. While circulation heaters are a cost-effective solution for generating steam, there are different material and design considerations to keep in mind. 

Materials Considerations

Circulation heaters are available in a wide range of materials. As with other inline heater variations, the target medium will determine the best material to use. However, in most steam applications, a user should choose between steel or Incoloy.  



Sheath Materials

Flange Materials

Process steam circulation heater

Steel, 304 stainless steel, 316 stainless steel, Incoloy

Carbon steel, carbon steel galvanized, 304 stainless steel, 316 stainless steel, Incoloy



A sheath for a process steam circulation heater should be made out of steel or a superalloy called Incoloy. Steel is commonly used as it can withstand high temperatures, and its price point is welcomed in many industrial settings. Although steel has limited corrosion resistance, it is ideal for this process heating application. 

Similarly, Incoloy is also an excellent sheath material for these inline heaters. As this material is either nickel or chromium-based, its corrosion resistance is high, and the material retains its strength at high temperatures. Fabrication of this material is easy as it uses the same processes and machines needed to fabricate steel. 



The flange material of a circulation heater for steam heating applications should also ideally be steel or stainless steel. The properties of these materials ensure that it is durable and has a low coefficient of thermal expansion. Galvanized steel may be another material consideration. However, it is essential to remember that although it has improved corrosion resistance, it isn’t as cost-effective. 


Design Considerations 

When considering a process steam circulation heater, you must also think of design considerations. For example, mounting, wattage, and flow rates may impact the size of the circulation heater you require. 


Circulation heaters for various process heating applications, including steam, are mounted horizontally or vertically. In most cases, mounting this form of inline heater will depend on preference or space allocation. 

For reference, the sizing of Wattco’s circulation heaters is standard. They feature a 1.25” NPT screw plug size to 14” diameter. Steel circulation vessels are fitted with flanges weighing 150 lbs. However, you can request special sizes, larger vessels, and heavier flanges. 


Many of Wattco’s circulation heaters and flanged heaters can be made with any power or voltage requirements. However, in the case of a process steam circulation heater, we advise a power rating of 1 – 350 kW. 

Control Panels

Wattco can provide a heater control panel for various process heating applications. Whether you are looking for ON/OFF logic or fully-proportional SCR control, our range of digital control panels is highly beneficial for the use of circulation heaters in industrial applications. 

Here are some options that you can consider: 

Browse our circulation heater product category for more information on process steam circulation heaters. Otherwise, contact us online and our team will be happy to answer any of your questions.