Stemco’s 351 Series bulb and capillary switches in liquid paint and fluid heaters deliver precise, mechanical control of fluid temperature. These devices regulate viscosity, stabilize process conditions, and protect equipment. We offer both adjustable models and dual-switch designs with an integrated manual reset limiter. For application support or system integration, contact us. For more information on our 351 series thermostats, visit the product page.
Thermal Control Using Bulb and Capillary Switches
Mechanical Temperature Regulation
Our bulb and capillary switches in liquid paint and fluid heaters use thermal expansion to actuate control. A fluid-filled sensing bulb reacts to heat, increasing pressure in the capillary tube. This pressure triggers the internal switch, controlling the heater circuit with no electronics or external sensors. The result is fast, accurate temperature management.
Adjustable and Dual-Switch Models
The 351 Series includes standard adjustable thermostats, allowing users to set the desired temperature for fluid regulation. We also manufacture a dual-switch configuration featuring one adjustable control and one manual reset high-limit switch. This design provides both operational temperature control and overtemperature protection in a single, compact unit.
Benefits in Paint Heating Systems
Consistent Fluid Properties
Bulb and capillary switches in liquid paint and fluid heaters maintain stable temperature, preventing viscosity changes that lead to coating defects. Accurate control supports proper atomization and consistent finish quality.
Designed for High-Pressure Environments
The 351 Series handles high operating pressures and flow rates. It integrates directly into single or dual-passage fluid heater systems, providing precise switching with minimal pressure loss.
Integrated Safety
The manual reset switch in our dual-sensor configuration acts as a safety cutoff, requiring physical reset after high-limit activation. This feature ensures fail-safe protection against thermal runaway.
Maintenance and System Compatibility
Fast, Tool-Free Replacement
Both the adjustable thermostat and manual reset switch are field-replaceable. Maintenance crews can perform service quickly, keeping system downtime to a minimum.
Flexible Mounting and Capillary Options
Mount bulb and capillary switches in liquid paint and fluid heaters either on the heater assembly or externally on a control panel. Multiple capillary lengths and compact footprints allow for easy integration into OEM and retrofit systems.
Built for Industrial Coating Applications
Our 351 Series supports the thermal demands of coating lines, spray systems, and process heating units. With adjustable and dual-switch models, Capillary Switch provides robust, field-proven control solutions for industrial heating systems.
To specify a 351 Series model for your application, contact us. We engineer reliable, mechanical control systems for bulb and capillary switches in liquid paint and fluid heaters.
