The Fischer Mess NK103000000100S0 is a mission-critical safety low-liquid-level limiter belonging to the specialized NK10 Series engineered and manufactured by FISCHER Mess- und Regeltechnik GmbH (Germany) – a globally recognized benchmark in industrial pressure, level, and thermal system safety instrumentation. The device is purpose-built to provide fail-safe low-level limitation (Low Level Limiter / Level Cut-Out) to prevent dry firing, excessive thermal stresses, and catastrophic tube rupture across organic heat transfer plants (thermal oil heaters) and industrial boiler plants.

The limiter functions via an internal stainless steel float mechanism coupled with a heavy-duty, hermetically separated permanent magnetic transmission system. If the liquid thermal oil level drops below the predetermined safe threshold, the magnetic float triggers an instantaneous changeover of the integrated safety switch contact, commanding the heating plant or burner management system to perform an emergency safety trip. Because the magnetic transmission operates completely contact-free across a non-magnetic chamber wall, dynamic seals and packing glands are completely eliminated, entirely preventing hazardous hot oil leaks into the atmosphere. Model NK103000000100S0 features a standard DN65 PN16 flange connection, robust capability to withstand severe continuous operating conditions up to 350°C medium temperature and 10 bar pressure. Most importantly, it holds full TÜV Type Approval certification conforming to DIN 4754 (safety requirements for heat transfer installations using organic heat transfer fluids) and fulfills functional safety standards up to SIL 2 / SIL 3, delivering absolute reliability for demanding thermal fluid boiler rooms.

• Manufacturer: FISCHER Mess- und Regeltechnik GmbH
• Brand Origin: Germany
• Full Order Code: NK103000000100S0
• Product Classification: Industrial Level Limiter / Safety Low Level Cut-Out (NK10 Series)
• Safety Function: Low liquid level limitation with fail-safe interlock trip for industrial burners/heaters
• Standards & Safety Approvals:
  - TÜV Component Type-Tested according to DIN 4754 (Heat transfer installations operating with organic heat transfer fluids)
  - Compliant with industrial boiler safety standards DIN EN 12952 / DIN EN 12953 / DIN EN 12828
  - Functional Safety Certification: Suitable for SIL (Safety Integrity Level) SIL 2 / SIL 3 architectures
• Compatible Media: Thermal oil (organic heat transfer fluids, synthetic/mineral thermal fluids), hot water, and high-temperature industrial process liquids
• Maximum Medium Temperature: Up to 350°C (fully optimized for high-temperature thermal oil systems)
• Maximum Operating Pressure: 10 bar (PN16 structural pressure rating)
• Mechanical Process Connection: Flange connection DN65 PN16 conforming to EN 1092-1 / DIN standards
• Sensing Principle: Mechanical float mechanism with non-contact permanent magnetic coupling (glandless, leak-free design)
• Electrical Output: Potential-free safety microswitch contact (changeover / bistable switching mechanism)
• Contact Electrical Rating: 250V AC, 2A / 24V DC
• Enclosure Protection Rating: IP65 according to EN 60529 (Total dust ingress prevention and water-jet resistance)
• Measuring Chamber & Body Materials: High-strength boiler steel P250GH combined with Stainless Steel 1.4571 (AISI 316Ti)
• Float Construction: Monolithic sealed high-grade stainless steel float engineered for elevated pressure and temperature
• Approximate Net Weight: 14 – 16 kg
• Ambient Operating Temperature at Terminal Enclosure: -20°C to +70°C
• Mounting Orientation: Vertical mounting on bypass chambers, expansion vessel balance lines, or thermal fluid vessels
• Industrial Safety Applications: Industrial thermal fluid boilers and heaters, thermal oil expansion vessels, textile/wood/food industrial drying and heating plants, steam boilers, and industrial hot fluid circulation skids