The FineTek SP series is a state-of-the-art thermal dispersion flow switch engineered for precise and reliable liquid flow monitoring. Operating on the calorimetric principle, it contains two temperature sensors: one heated and one reference. As liquid flows past the heated sensor, it creates a cooling effect; the resulting temperature difference between the two sensors is directly proportional to the flow velocity. This design eliminates all moving parts, providing maintenance-free operation, long-term reliability, and immunity to issues like clogging or mechanical wear.

Core Features

• Maintenance-Free Operation: With no moving parts, the SP series eliminates common failure points such as seized paddles, broken springs, or worn bearings, significantly reducing downtime and lifecycle costs.
• High Pressure and Temperature Ratings: Rated for operating pressures up to 100 bar (1450 psi) and media temperatures from -20°C to +85°C (with high-temperature options available), suitable for demanding industrial environments.
• Wide Application Compatibility: Detects flow in a broad range of liquids, from water and oil to corrosive chemicals, with wetted material options including 304/316 stainless steel, PVDF, and polypropylene.
• Flexible Configuration: Available with multiple output options (NPN/PNP, relay, SPDT) to interface with various control systems. Standard and custom extended insertion lengths are offered to match different pipe sizes.
• LED Flow Status Indication: Integrated LEDs provide a clear, local visual indication of flow status, simplifying commissioning and troubleshooting.
• Hazardous Area & Marine Certifications: Optional explosion-proof units (for hazardous areas) and marine-certified units are available for specialized applications.

Technical Specifications

• Power Supply: 24 V DC ±10%
• Output Options:
  • NPN or PNP open collector (250 mA max)
  • SPDT relay (0.3A @ 125V AC / 1A @ 30V DC)
  • Relay with NO/NC selection
• Switch Point Adjustment: User adjustable via potentiometer
• Switch Point Hysteresis: Approx. 5% of set point
• Response Time: 1 to 10 seconds (adjustable)
• Warm-up Time: < 30 seconds
• Electrical Connection: M12 plug connector (4-pin) or cable gland
• Process Connection: G1/2, G3/4, G1 threads (standard); NPT threads available
• Insertion Length: Standard 1" to 8" (25-200mm); custom lengths available
• Medium Temperature (Standard): -20°C to +85°C
• Medium Temperature (High Temp Option): -20°C to +120°C
• Ambient Temperature: -20°C to +70°C
• Storage Temperature: -40°C to +85°C
• Protection Rating: IP65 (standard) / IP67 (optional)
• Housing Material: Stainless steel (316SS) or aluminum alloy
• Certifications: CE, optional ATEX/IECEx (explosion-proof), optional Marine (DNV, etc.)

Applications

The SP series is widely deployed in industrial applications requiring reliable, low-maintenance liquid flow monitoring:

• HVAC Systems: Chilled water, hot water, and cooling tower flow monitoring.
• Petrochemical & Chemical Processing: Corrosive chemical flow detection, pump dry-run protection.
• Power Generation: Cooling water monitoring for turbines and generators.
• Food & Beverage Processing: Sanitary liquid flow monitoring (with PVDF or SS options).
• Pharmaceutical Manufacturing: WFI (Water For Injection) and purified water system flow monitoring.
• Water Treatment: Chemical dosing and filter monitoring.
• Semiconductor & Optics: High-purity chemical flow detection and cooling pipe control.
• Shipbuilding & Marine: Ballast water and seawater cooling systems (marine-certified units).