Thermal Flow Switch

What is a Thermal Flow Switch?

A Thermal Flow Switch is a precision electronic device used to monitor and control the flow of liquids or gases by sensing temperature differences caused by the moving medium. It consists mainly of a sensor probe, an electronic control unit, and a protective housing made of cast aluminum or stainless steel.

When the medium flows, heat transfer occurs between the heated sensor and the fluid. The switch detects this change and outputs an electrical signal, indicating flow or no-flow status.

ZINACA Instruments is a professional thermal flow switch manufacturer, offering various models including Standard, Explosion-proof, Digital, and High-Temperature Explosion-proof Thermal Flow Switches—widely used in industrial automation, fluid monitoring, and process control systems.

Types of Thermal Flow Switch

Standard Thermal Flow Switch:
Designed for general-purpose industrial applications such as water treatment systems, cooling loops, and HVAC control. It offers stable performance, simple installation, and reliable flow detection for most liquid and gas media.

Explosion-Proof Thermal Flow Switch:
Suitable for use in hazardous areas such as oil & gas plants, refineries, and chemical industries. Equipped with an explosion-proof aluminum or stainless steel housing to ensure safe and stable operation under harsh conditions.

Digital Thermal Flow Switch:
Features a digital display and adjustable parameters for real-time monitoring. Ideal for precision flow control in industries like chemical processing, food production, and automation systems.

Explosion-Proof Thermal Flow Switch (for High Temperature & High Viscosity Media):
Specially developed for challenging environments with high temperature or high-viscosity fluids, such as lubricating oil systems, heavy oil transport, and high-viscosity chemical processes. It provides stable and accurate flow detection even under extreme conditions.

Flow and Temperature Integrated Flow Switch

Features of Thermal Flow Switch

No moving parts — maintenance-free and long service life

Suitable for both liquid and gas applications

Optional stainless steel or cast aluminum housing

High sensitivity and quick response time

Adjustable setpoint and LED indication for flow status

Output options: Relay, PNP/NPN transistor, or analog signal

Explosion-proof and high-temperature models available

Applications of Thermal Flow Switch

Thermal flow switches are widely used in:

Oil & gas and petrochemical industries

Chemical and pharmaceutical process control

Water and wastewater treatment systems

Air compressor and pneumatic systems

Cooling water and HVAC systems

Food and beverage processing lines

Thermal Flow Switch OEM Service

ZINACA Instruments provides complete OEM and ODM services for thermal flow switches.
We can customize:

Housing: cast aluminum or stainless steel

Sensor probe material: SS316L, SS304, or PTFE (Teflon) for special corrosive media

Output signal and measurement range

Branding, labeling, and packaging

Thermal Flow Switch Manufacturer

Tianjin ZINACA Intelligent Equipment Co., Ltd. is a leading manufacturer specializing in thermal, paddle, and piston flow switches.

With advanced production technology, strict quality control, and ISO/SIL certifications, ZINACA delivers reliable, high-precision, and durable flow instruments for global industrial customers.
If you are looking for a trustworthy thermal flow switch supplier, choose ZINACA Instruments — your reliable partner in industrial automation.

FAQ for Thermal Flow Switches

Q1: How do I select the right Thermal Flow Switch model for my application?

A: Key factors to consider include: the media type (liquid/gas, cleanliness), temperature range (high or low temperature), pressure requirements, whether explosion-proof certification is needed, and whether you require simple flow monitoring or integrated flow and temperature monitoring.

Q2: What is the working principle of a Thermal Flow Switch, and how low a flow rate can it detect?

A: It operates based on the Thermal Dispersion principle. It consists of a heated element and a temperature-sensing element. As the flow rate changes, the amount of heat carried away changes, which alters the temperature difference between the two elements, thus triggering the switch. It is typically well-suited for detecting low flow rates or minor flow changes.

Q3: Can your Thermal Flow Switches be used with high-viscosity media and in high-temperature environments?

A: Yes, they can. Our specialized Explosion-proof Thermal Flow Switch (for High Temperature & High Viscosity Media) is designed for these demanding conditions. It ensures accurate and reliable operation in high-viscosity media (e.g., oils, heavy fuel oil) and high-temperature environments (e.g., superheated steam).

Q4: What are the special features of the Flow and Temperature Integrated Flow Switch?

A: This model provides both flow monitoring and temperature monitoring functions within a single device. This integration helps save installation space and cost, and simplifies system wiring. It is particularly suitable for applications that require simultaneous monitoring of these two critical parameters.

Q5: Do Thermal Flow Switches require regular maintenance or calibration?

A: Thermal Flow Switches are typically designed to be low-maintenance. However, to ensure long-term accuracy, we recommend periodically checking the probe for any signs of fouling or corrosion. Our digital models often support easier in-situ (on-site) calibration.

If you are still unsure which model is the best fit for your application, please contact our engineers for a free selection consultation!