Hemomatik Nivakt HMFB-OT Liquid Level & Temperature Switch O=300 T=70°C Sensor

Hemomatik NIVAKT HMFB‑OT is a combined liquid level and temperature switch designed for monitoring hydraulic oil, lubrication oil or water level in tanks and reservoirs. The unit features a vertical brass float rod with magnetic float and a top‑mounted polyamide junction box with screw terminals for easy electrical connection.

This item is new old stock, never used, with minor storage marks only and no signs of installation or wiring. It is suitable for industrial users, maintenance departments and hobby builders who need a robust float switch for machine tanks, hydraulic power units or custom fluid reservoirs.

Brand and model

• Brand: Hemomatik NIVAKT (Sweden)

• Model: HMFB‑OT

• Type: Liquid level and temperature switch (float switch with thermostat)

• Marking on label: “HMFB‑OT O=300 T=70°C”

Technical specifications

• Measuring function: Combined level switch and over‑temperature switch

• Immersion length O: 300 mm (approximate rod length from mounting face to float)

• Temperature switch set point: Opens at about 70 °C, resets at about 50 °C (standard T=70°C version).

• Process connection: G1 (R1") male thread with mounting flange and gasket groove.

• Electrical rating (typical HMFB series): up to 300 V AC, max 3 A / 100 VA for level contact, 1 A / 100 VA for temperature contact – actual rating depends on installation and must follow datasheet and local regulations.

• Contact function: Reed switch, normally closed at low level, opens on falling level (O‑type contact).

• Material: Brass float stem, plastic (polyamide) junction box, nitrile rubber sealing gasket (standard HMFB design).

• Medium: Typically mineral oil, lubrication oil or water‑based fluids up to about 80 °C.

Main features

• Integrated level and temperature monitoring in a single compact probe, reducing tank penetrations and wiring.

• Magnetic float technology with sealed reed switches for long service life and no mechanical linkage inside the junction box.

• Top‑mounted threaded connection and flange allow installation from above with good sealing and simple maintenance access.

• Screw‑terminal junction box with cable gland for secure field wiring and strain relief.

• Designed for demanding industrial environments such as hydraulic power packs, marine equipment and lubrication systems.

Condition and packaging

• Condition: New old stock (NOS); never installed, never wired, from spare‑parts inventory.

• Visual state: May show dust, light scratches or minor storage marks on housing and rod; float moves freely and threads are clean.

• Supplied as shown in the photos, without original box or documentation. Any mounting screws or gaskets visible in the pictures are included.

Notes for buyers

This Hemomatik NIVAKT HMFB‑OT sensor is ideal as a replacement level/temperature switch in existing hydraulic or lubrication systems that already use the HMFB series. It may also be suitable for custom machinery or experimental setups where a reliable float‑type level contact and simple 70 °C over‑temperature alarm are required, but buyers should confirm dimensions and electrical ratings against their application before purchase