Description
The QSKF is a calorimetric flow switch in a painted cast aluminium housing, described as an explosion-proof version. It is particularly suited to water, cutting fluid, lubricating oil and air in pneumatic and hydraulic systems, and to pump dry-running protection.
A heated and an unheated resistor in the probe sense the flow velocity. Setting range: 1 … 150 cm/s water, 3 … 300 cm/s oil, 20 … 2000 cm/s air, by a potentiometer with the cover unscrewed. Accuracy and repeatability are not documented. Output PNP, NPN or relay (SPDT), switching current ≤ 400 mA or ≤ 4 A (relay). Supply 24 V DC ± 20 %, no-load current ≤ 80 mA, response time 1 … 13 s, typically 2 s. Terminal strip in the housing, M20 × 1.5 cable entry.
Probe in stainless steel, housing in cast aluminium, painted. Process connection G1/2, G1/4, Rc1/2 or Rc1/4 male or M18 × 1.5 female. Pressure rating 100 bar, medium temperature -20 … +80 °C, protection IP67. The datasheet states Ex d IIC T6; a certificate is not documented. A declaration of conformity is not documented in the datasheet. Before sizing, note: The explosion protection is optional in the order code, and a certificate and a separate ambient range for explosion-proof service are missing. Data block and order code disagree on the supply; only 24 V DC can be ordered. The setting range is a flow velocity; the flow rate depends on the pipe bore.
Advantages at a glance
- Calorimetric principle with no moving parts
- Housing in painted cast aluminium
- Output PNP, NPN or SPDT relay
- M20 × 1.5 cable entry with terminal strip
- Pressure rating 100 bar at the switch
- Protection IP67
- Eight LEDs behind a window