Side-Mounted Level Switch for Industrial Tank Applications
The KOBOLD NKP is an economical side mount level switch designed for reliable liquid level detection in industrial tanks and vessels. Available in polypropylene or PVDF construction, the NKP provides excellent chemical resistance for aggressive liquids across chemical processing, water treatment, and industrial manufacturing applications. The compact horizontal mounting design makes the NKP ideal for tanks with inaccessible tank tops or bottoms.
This side-mounted float switch delivers reliable switching performance with minimal maintenance requirements, featuring a magnetic float assembly with a high-capacity reed switch to provide instant response as liquid levels rise or fall. Installation is simple through standard 1/2" NPT, G 1/2, or M16 bulkhead connections, and the switch function can be easily reversed from normally open to normally closed by rotating the unit 180 degrees.
Chemical Resistant Materials for Aggressive Liquids
The NKP is available in two material configurations to accommodate different process requirements. The polypropylene version offers broad chemical compatibility with many acids, bases, and solvents, operating at temperatures up to 176°F (80°C) with minimum liquid densities of 0.6 specific gravity.
For more demanding chemical applications, the PVDF version provides enhanced chemical resistance to strong acids, oxidizers, and chlorinated compounds, with operating temperatures up to 212°F (100°C) and compatibility with liquids down to 0.95 specific gravity. Both versions feature IP68 protection for reliable performance in full immersion environments.
Compact Design for Space-Constrained Installations
The horizontal mounting configuration of the NKP makes it particularly well-suited for shallow tanks, rectangular vessels, and installations where vertical clearance is limited. The compact float assembly extends only 2.68 inches (68 mm) into the tank, minimizing interference with internal components or agitation systems. The unit mounts horizontally through the tank sidewall with an orientation tolerance of ±30 degrees, providing installation flexibility in various tank geometries.
Reversible Contact Function for Installation Flexibility
The NKP features a field-selectable normally open or normally closed signal without requiring different part numbers or internal modifications. By simply rotating the switch body 180 degrees during installation, operators can configure the function to match their specific control logic requirements. This reversible design simplifies inventory management and reduces the risk of ordering errors while providing maximum flexibility for pump control, high-level alarms, or low-level cutoff applications.
Hermetically Sealed Reed Switch for Long Service Life
The heart of the NKP is a watertight, hermetically sealed reed switch rated for 230 VAC/VDC at 2 amps with 40 VA maximum power. The sealed enclosure isolates the electrical contacts from the process environment, eliminating exposure to moisture, chemicals, or contamination that can cause premature switch failure. This design ensures reliable switching performance over millions of cycles without calibration or adjustment. The reed switch actuates through magnetic coupling, with no mechanical linkages or seals that require maintenance.
Common Applications
The NKP side-mounted level switch is widely used for tank level control, pump automation, and process monitoring across multiple industries. Typical applications include chemical storage tanks, water treatment systems, industrial process vessels, wastewater collection tanks, and liquid transfer operations. The switch is commonly specified for high-level alarm systems, low-level pump protection, batch process control, and automatic filling operations where reliable point-level detection is required.
Made in USA Manufacturing and BABA Compliance
The NKP level switch is manufactured at KOBOLD's Pittsburgh, Pennsylvania facility, ensuring domestic production and compliance with Build America, Buy America Act (BABA) requirements. This Made in USA manufacturing makes the NKP an approved solution for federal infrastructure projects, state and municipal water systems, and government facilities that mandate domestic content. The domestic manufacturing also provides responsive technical support, short lead times, and reduced supply chain complexity for North American customers.
Technical Specifications Summary
The NKP operates at maximum pressures up to 145 PSIG across its temperature range. Available connection options include 1/2" NPT, G 1/2, and M16 bulkhead fittings to accommodate various tank wall configurations and thicknesses (up to 0.20 inches for bulkhead mounting). Standard cable lengths include 1 meter, 1.6 meters, 3 meters, 6 meters, and 10 meters, with custom lengths available for special installations. The PVC-jacketed AWG 20/2 cable provides durable electrical connection in industrial environments.
Maintenance-Free Operation
The simple mechanical design of the NKP requires virtually no maintenance during its service life. With no mechanical seals, shaft penetrations, or wearing components, the switch operates reliably year after year without adjustment or calibration. The sealed reed contact eliminates contact oxidation and degradation, while the hinged float assembly moves freely without lubrication requirements. This maintenance-free design reduces total cost of ownership and minimizes process downtime.
Common Questions about NKP - Side-Mounted Level Switch
A hinged plastic float containing a magnet rides up and down with the liquid inside the vessel. As the float passes the switch point, its magnet operates an encapsulated reed contact, opening or closing the circuit. Actuation is purely magnetic, so nothing mechanical passes through the tank wall to wear or leak.
Mounting position sets the contact action. Install the NKP in one orientation for an N/O contact; invert the same unit 180 degrees for an N/C contact. One part number covers both control schemes, which simplifies spares stocking and lets the function be decided at installation time rather than at ordering.
The medium must be chemically compatible with the wetted material, polypropylene or PVDF, and must meet the minimum density: 0.6 specific gravity for polypropylene models and 0.95 for PVDF models. Liquids should also be free of solids or ferrite particles, which could collect on the float magnet and interfere with switching.
Yes. Level control is often accomplished with at least two level switches, one sensing the minimum level and the other detecting the maximum. Because each NKP can be set to either contact action at installation, a pair of identical units can cover both points in a fill or empty circuit.
Mount the switch on a horizontal axis, within 30 degrees of horizontal, positioned so the float can travel its full path without hitting walls, floor, or fittings. Avoid locations exposed to heavy turbulence from agitators or inlet valves, and torque the mounting nut to 4 Nm on M16 bulkhead models.
No. The level switch is totally insulated, so a protective grounding conductor is not required. Wiring is a simple two-conductor hookup using the supplied AWG 20 PVC cable. Confirm the supply voltage matches the device nameplate and de-energize supply lines before making the connection, according to specifications.
The PVC cable comes in standard lengths of 1, 1.6, 3, 6, and 10 meters; special lengths over 10 meters can be specified in clear text on the order. A cCSAus-approved version is available as option C in the order code, rated 0.17 A at 230 V per its approval.
Maximum media temperature depends on the wetted material: 176°F (80°C) for polypropylene and 212°F (100°C) for PVDF. Maximum working pressure is 145 PSIG (10 bar) for both versions, according to specifications. Applications should stay within both limits at the same time, since they apply together in service.
Average electrical contact life depends on load, according to specifications: about 100,000 switching operations at maximum electrical load, 50 million at half load, and 100 million at low load (under 10 V and 1 mA). Switching low-power signals rather than full loads therefore extends service life considerably.
Yes. Production takes place at the company's Pittsburgh, Pennsylvania plant, satisfying Build America, Buy America Act domestic-content requirements. That allows the switch to be specified on federal infrastructure work, municipal water projects, and other government contracts where domestic manufacture is mandated.