STEMCO Capillary Switch

Capillary Thermostat Switch Descriptions

Fluid Filled Capillary Thermostats

No matter which style or model you choose, all of the capillary thermostats operate using the same physics. A fluid is encapsulated in a metal and when the temperature changes the fluid either expands or contracts. This fluid change moves a diaphragm which is in touch with a snap action switch and either opens or closes a circuit. Our thermostats also offer the option of being ambient compensated to offset the differential in temperature which keeps our thermostat controls more accurate as it’s environment changes.  Thermowells and Enclosures are also available with all models.

All of the Stemco, Cemco and Essex International Capillary Thermostat switches built by Senasys can also be built to customer specifications. This insures you get the exact control you want without paying for features you don’t need.


351 Series Capillary Thermostats351 Series Capillary Thermostats

The 351 series Capillary Thermostat is a versatile line of remote sensing thermostats available in Bulb and Capillary Tube or Probe styles. Many variations are available in each style to include fixed or adjustable temperatures, auto or manual resets, Copper/Plated Copper or Stainless steel  construction and all variations have multiple mounting options.

The Screwdriver adjustable model with front connect terminals is perfect for warming ovens, deep fat fryers and commercial water heaters.

The D shaft style is adjustable and is used with a knob which is great for convection ovens, charbroilers, grills, toaster ovens and dishwashers.

The fixed temperature models are typically used for safety or high and low limit applications.

All options are available in both the probe style more typical of a boiler type installation or as a Bulb and capillary tube for more remote temperature sensing.

Calibration Range        0°F – 700°F                              Switch Action                    SPDT

Range Options             Fixed or Adjustable                   Switch Ratings                 15-30 Amps

Reset Options              Automatic or Manual                  Max Ambient                     250°F

View 351 Series Capillary Thermostat Specifications

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352 Series Capillary Thermostats

The 352 series capillary thermostat offers the addition of a second switch which opens the range of applications for a capillary thermostat. The 2 switches can be any combination of SPDT automatic reset and or SPST manual reset. The differential between the 2 switches can be factory set very close for Double Pole applications or widened out for multistage applications.  Combination of heating and cooling or fan and limit from one thermostat. Use it for 3 phase or double line breaks.  This series leaves applications wide open.

Calibration Range  0°F – 700°F                  Switch Action                    2 SPDT

Range Options       Fixed or Adjustable       Switch Ratings                  15-30 Amps per switch

Reset Options        Automatic or Manual      Max Ambient                     250°F

View 352 Series Capillary Thermostat Specifications

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354 Series Capillary Thermostats

The 354 series capillary thermostats uses a through shaft design which offers a smooth accurate movement. Combined with tight tolerances you get repeatability through the entire dial rotation. Side mounting is ideal in areas of limited depth.  The 354 series can be used for a wide variety of control functions including Spas, Pool Heaters, Wall Heaters, Heat Pumps, Fan controls, and commercial Ranges and Food Service Equipment.

Calibration Range         0°F – 675°F                            Switch Action                    SPDT

Range Options               Fixed or Adjustable                Switch Ratings                 15-25 Amps

Reset Options                Automatic                                Max Ambient                    150°F

View 354 Series Capillary Thermostat Specifications

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358 Series Capillary Thermostats

The 358 Series capillary thermostats offers the same versatility as the 351 series w358 Series Capillary Thermostatsith the addition of being a more compact design. The 358 series close tolerances and narrow temperature differential make it ideal for commercial cooking equipment, Water Heaters and Dishwashers. The mounting is available with standard centers of 1.75”, 1.312” and 28mm making it an easy replacement thermostat. All 359 series are available in Copper, Plated Copper and Stainless Steel construction.

The Screwdriver adjustable model with front connect terminals is perfect for warming ovens, deep fat fryers and commercial water heaters.

The D shaft style is adjustable and is used with a knob which is great for convection ovens, charbroilers, grills, toaster ovens and dishwashers.

The fixed temperature models are typically used for safety or high and low limit applications.

Calibration Range         0°F – 700°F                           Switch Action                   SPDT

Range Options               Fixed or Adjustable               Switch Ratings                15-30 Amps

Reset Options                Automatic or Manual              Max Ambient                    250°F

View 358 Series Capillary Thermostat Specifications

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368 Series Capillary Diaphragm Assemblies

The 368 Series is also known as 368 Hydrastat diaphragm assembly. It consists of a Bulb, Capillary Tube and a diaphragm. The diaphragm is engineered for a specific movement at a given temperature change. The 368 Hydrastat is the same diaphragm assembly used in the 350 line up of thermostat controls. These are available in Copper, Plated copper or Stainless Steel.

View 368 Series Bulb and Capillary Thermostat Specifications

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Thermowells & Support Tubes

Thermowells are tubular fittings used to protect temperature sensors installed in industrial processes. A thermowell consists of a tube closed at one end and mounted in the process stream. We currently produce several varieties that house both RTD’s and our Temperature Sensing Capillary Probes. Combinations of materials such as brass fittings with stainless steel  or copper tubes are our standard models.

Click here for more options and information on our thermowells and support tubes.

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