Product Overview

The NOIKE-AH Anti-Corrosion Explosion-Proof Flow Switch NK33EX is a high-performance electronic flow switch designed for reliable flow monitoring in hazardous and corrosive industrial environments. Utilizing advanced thermal dispersion technology, the NK33EX accurately detects the flow of liquids, gases, and oils without any moving mechanical parts, ensuring long-term stability and maintenance-free operation.

The sensor probe features a special anti-scaling coating that effectively prevents deposits, rust, and impurities from adhering to the sensing surface, making it ideal for harsh process conditions. Certified with Ex db IIC T6 Gb and Ex tb IIIC T80°C Db explosion-proof ratings, the NK30EX provides dependable flow protection for petrochemical, power generation, water treatment, and other hazardous-area applications.

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Working Principle

The Anti-Corrosion Explosion-Proof Flow Switch NK33EX operates using the thermal dispersion principle.

Inside the probe are two precision temperature sensors:

• A heated sensing element
• A reference temperature element

When there is no fluid flow, the heated sensor maintains a constant temperature difference. As the process medium begins to flow, heat is carried away from the heated sensor. The electronic circuit continuously measures the temperature difference between the two sensors and calculates the flow condition.

When the measured flow reaches the preset switching point, the device outputs a switching signal for pump protection, process control, or alarm functions.

Because the measurement is based on heat transfer rather than moving mechanical components, the NK33EX offers excellent reliability, fast response, and outstanding durability.

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Product Features

• Thermal dispersion technology with no moving parts
• Suitable for liquids, oils, and gases
• Explosion-proof design for hazardous areas
• Anti-scaling coated probe minimizes contamination and maintenance
• 6-LED flow status indicator for visual monitoring
• Adjustable flow switching point
• PNP, NPN, relay (SPDT) output options
• Reverse polarity, overload, and short-circuit protection
• High pressure resistance up to 100 bar (optional up to 40 MPa)
• Excellent repeatability of ±2%
• Compact, rugged cast aluminum housing
• IP67 protection for harsh industrial environments

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Technical Specifications

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Typical Applications

The Anti-Corrosion Explosion-Proof Flow Switch NK33EX is suitable for flow monitoring and equipment protection in hazardous industrial environments, including:

Oil & Gas

• Pipeline flow monitoring
• Pump protection
• Lubrication systems
• Cooling systems

Petrochemical Industry

• Chemical process control
• Corrosive liquid monitoring
• Hazardous area flow detection

Power Generation

• Cooling water systems
• Boiler circulation
• Heat exchanger protection

Water & Wastewater Treatment

• Pump dry-run protection
• Filtration systems
• Chemical dosing equipment

Food & Beverage

• CIP cleaning systems
• Cooling circuits
• Process water monitoring

Paper & Pulp Industry

• Lubrication systems
• Cooling water circulation
• Chemical process monitoring

General Industrial Automation

• Hydraulic systems
• Compressor cooling
• Machine tool coolant monitoring
• Process control systems

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Advantages

Compared with traditional paddle or mechanical flow switches, the NK33EX offers:

• No moving parts for maintenance-free operation
• High reliability and long service life
• Excellent resistance to scaling and contamination
• Suitable for both liquids and gases
• Fast and accurate switching response
• High pressure and temperature capability
• Explosion-proof certification for hazardous environments
• Easy installation and simple adjustment

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Why Choose the NOIKE-AH NK33EX?

The NOIKE-AH Anti-Corrosion Explosion-Proof Flow Switch NK33EX combines advanced thermal dispersion sensing, anti-scaling technology, and certified explosion-proof protection into a compact, durable solution. Designed for demanding industrial applications, it provides accurate flow monitoring, reliable pump protection, and long-term maintenance-free performance, making it the ideal choice for oil & gas, chemical processing, power generation, water treatment, and other hazardous-area industries.

Wiring Diagram

Dimensional Drawing (mm)

Frequently Asked Questions (FAQ)

1. What is the Anti-Corrosion Explosion-Proof Flow Switch NK33EX?

The NK33EX is a high-performance electronic flow switch designed for reliable flow monitoring in hazardous and corrosive industrial environments. It utilizes advanced thermal dispersion technology with no moving mechanical parts, ensuring long-term stability and maintenance-free operation.

2. What is the working principle of this product?

The NK33EX operates based on the thermal dispersion principle. The probe contains two precision temperature sensors (a heated sensing element and a reference temperature element). As the medium flows, heat is carried away, and the electronic circuit continuously measures the temperature difference between the two sensors to calculate the flow condition and output a signal when a preset switching point is reached for pump protection, process control, or alarms.

3. What measuring media are supported by the NK33EX?

It is suitable for liquids, oils, and gases. The setting ranges for different media are as follows:

• Water: 1–150 cm/s

• Oil: 3–300 cm/s

• Gas: 20–2000 cm/s

4. What are the explosion-proof and protection ratings of the product?

• Explosion-proof Rating: Ex db IIC T6 Gb / Ex tb IIIC T80°C Db

• Protection Class: IP67 (suitable for harsh industrial environments)

5. What is the anti-contamination capability of the NK33EX probe?

Its sensor probe features a special anti-scaling coating that effectively prevents deposits, rust, and impurities from adhering to the sensing surface, making it ideal for harsh process conditions and reducing maintenance.

6. What output signal options are available?

Output signal options include PNP, NPN, and Relay (SPDT NO/NC).

7. What are its pressure and temperature limits?

• Pressure Rating: Standard 100 bar (optional up to 40 MPa)

• Medium Temperature: -20°C to +100°C (optional -60°C to +150°C)

• Ambient Temperature: -20°C to +80°C

8. What industries are the primary applications for the NK33EX?

It is widely used in oil & gas, petrochemical industries, power generation, water and wastewater treatment, food and beverage, paper and pulp industries, and general industrial automation (such as pipeline flow monitoring, pump protection, cooling systems, and chemical process control).