A sepia-tinted photo of and antique boiler.Boilers are relatively simple machines that can be used for a variety of purposes: water heating, central heating in homes and other buildings, to generate steam for power, sterilization, cooking, and more. Composed in the most basic sense of a metal pressure vessel that contains the fluid to be boiled, a source of energy to heat it, and some method of output (configuration will depend on the purpose of the boiler as well as other variables).

For most if not all boiler configurations, float switches or other liquid level sensors are absolutely essential to their proper and safe function. Applications for float switches in boilers include:

  • Water high level alarms to prevent overflow or explosion
  • Low level cutoff to prevent damage to boiler systems
  • Pump controls for boiler feed-water
  • And more

Boiler Switch Options from SMD Fluid Controls

FH13 Side-Mounted Horizontal Float Switch

The FH13 is made from durable stainless steel and boasts a maximum operating temperature of 120°C and can withstand pressures of up to 125 PSI. This high heat resistance makes it ideal for boiler applications where point level detection is required, such as high-level alarms or shut-off controls, and side-mounting is desirable.

FS21 Vertical Float Switch

Even more durable than the FH13, the FS21 is capable of withstanding temperatures of up to 150°C and pressures of 200 PSIG. Ideal applications are also point-level in nature.

Options for Continuous Level Measurement

If you have a boiler application requiring continuous level measurement, SMD Fluid Controls also has options for you. Our FLL ultrasonic level sensor uses ultrasonic sound waves as a detection method, meaning contact with the liquid medium is unnecessary. Capable of withstanding pressures well in excess of the FH13 and FS21, the FLL’s maximum operating temperature is only 90°C, meaning it might not be suited for all boiler applications. With a maximum operating temperature of 125°C, the OS150 optical level sensor might be a better choice for non-contact, continuous level measurement in boiler applications.

Custom Solutions from SMD Fluid Controls

Of course, these are only some of the options offered by SMD Fluid Controls. In addition to numerous other off-the-shelf float switch models, SMD can also work with you to create custom designs to meet the needs of your specific application. Custom options include mounting, switch length, integrated electronics, integrated temperature sensors, and more.


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