Explosion-Proof Thermal Flow Switch NK33EX-600 | Corrosion-Resistant Flow Switch for Hazardous Areas

Brand: NOIKE-AH
Range:‌ NK33EX-600

Specification

Product Overview

The NOIKE-AH Explosion-Proof Thermal Flow Switch NK33EX-600 is a corrosion-resistant electronic flow switch designed for reliable flow monitoring in hazardous industrial environments. Utilizing thermal dispersion technology, it accurately detects the flow of water, oil, and air without any moving parts, ensuring maintenance-free operation and long-term reliability.

Certified with ExdII CT6 explosion protection and an IP67 enclosure, the NK33EX-600 is ideal for pump protection, coolant monitoring, lubrication systems, and industrial process control in petrochemical, chemical, power, and manufacturing industries.

Key Features

Thermal dispersion flow measurement
Explosion-proof design for hazardous areas
Corrosion-resistant stainless steel construction
Suitable for water, oil, and air
No moving parts for maintenance-free operation
6-segment LED flow indication
Adjustable switching point via potentiometer
Supports PNP, NPN, and relay (SPDT) outputs
Reverse polarity, short-circuit, and overload protection
High-pressure capability up to 100 bar
IP67 protection for harsh industrial environments

Working Principle

The Explosion-Proof Thermal Flow Switch NK33EX-600 operates using the thermal dispersion principle.

A heated sensing element and a reference element are integrated inside the sealed probe. As fluid flows past the probe, heat is transferred away from the heated element. The electronic circuit continuously measures the temperature difference between the two elements to determine the flow velocity.

When the measured flow reaches the user-defined switching point, the flow switch activates the selected output signal. Since there are no moving mechanical components, the sensor provides stable performance, fast response, and long service life with minimal maintenance.

Technical Specifications

Parameter	Specification
Measuring Principle	Thermal Dispersion
Suitable Media	Water, Oil, Air
Flow Range	Water: 1–150 cm/s
	Oil: 3–300 cm/s
	Air: 20–2000 cm/s
Output Signals	PNP, NPN, Relay (SPDT: NO + NC)
Power Supply	24 VDC ±20%
Maximum Switching Current	400 mA (PNP/NPN)
Relay Rating	1 A @ 48 VAC/DC
Standby Current	≤80 mA
Flow Indication	6-segment LED bar
Setting Method	Potentiometer
Pressure Rating	100 bar
Temperature Gradient	≤4°C/s
Response Time	1–13 s (Typical 2 s)
Initialization Time	8 s
Electrical Protection	Reverse polarity, short circuit, overload protection
Explosion-Proof Rating	ExdII CT6
Protection Rating	IP67
Medium Temperature	-20°C to +100°C
Ambient Temperature	-20°C to +80°C
Storage Temperature	-20°C to +100°C
Connection	M12 Connector
Repeatability	±2%

Materials

Component	Material
Probe	Stainless Steel
Housing	Stainless Steel

Typical Applications

The Explosion-Proof Thermal Flow Switch NK33EX-600 is suitable for a wide range of industrial applications, including:

Pump dry-run protection
Coolant flow monitoring
Lubricating oil systems
Hydraulic systems
Pneumatic systems
Industrial cooling circuits
Process water monitoring
Chemical processing
Petrochemical plants
Power generation
Manufacturing automation

Product Advantages

Explosion-proof design for hazardous environments
Corrosion-resistant stainless steel construction
Suitable for both liquid and gas applications
No moving parts for maintenance-free operation
High-pressure resistance up to 100 bar
Low maintenance and long service life
Fast response with adjustable switching point
Multiple industrial output options
LED flow indication for quick status monitoring
Reliable performance in demanding industrial processes

Installation Recommendations

For optimum performance:

Install according to the indicated flow direction.
Ensure the probe is fully exposed to the process medium.
Use the supplied M12 connector for secure electrical connections.
Verify the 24 VDC power supply before energizing the device.
Adjust the switching threshold using the built-in potentiometer after installation.
Periodically inspect and clean the probe when used with contaminated media.

Industries Served

Oil & Gas
Petrochemical
Chemical Processing
Power Generation
Water Treatment
Machinery Manufacturing
Industrial Automation
HVAC
Hydraulic Equipment
Pneumatic Systems
Process Control

Frequently Asked Questions (FAQ)

What media can the NK33EX-600 monitor?

The NK33EX-600 is designed to monitor water, oil, and air, making it suitable for both liquid and gas applications.

Does the flow switch have moving parts?

No. It uses thermal dispersion technology with no moving mechanical components, providing maintenance-free operation and long-term reliability.

What output options are available?

The device supports PNP, NPN, and SPDT relay (Normally Open + Normally Closed) outputs.

Is it suitable for hazardous areas?

Yes. The NK33EX-600 is rated ExdII CT6, making it suitable for installation in explosion-proof industrial environments where this certification is applicable.

Can it protect pumps from dry running?

Yes. The flow switch is commonly used for pump dry-run protection, coolant monitoring, and lubrication system flow detection.

What is the maximum operating pressure?

The standard pressure rating is 100 bar.

How is the switching point adjusted?

The switching threshold is easily adjusted using the integrated potentiometer.

What is the enclosure protection rating?

The NK33EX-600 has an IP67 enclosure rating, providing excellent protection against dust and water ingress.

Ordering Information

When placing an order, please confirm the following:

Product model
Required flow measurement range
Output signal type (PNP, NPN, or Relay)
Required accessories or optional configurations

Why Choose the NOIKE-AH Explosion-Proof Flow Switch NK33EX-600?

The NOIKE-AH Explosion-Proof Thermal Flow Switch NK33EX-600 combines thermal dispersion technology, explosion-proof protection, and corrosion-resistant stainless steel construction into a compact, maintenance-free flow switch. With flexible output options, high-pressure capability, and reliable performance in hazardous industrial environments, it is an ideal solution for pump protection, cooling systems, hydraulic equipment, and industrial process automation.