The Rotameters RAGK and RAGL are specifically designed for the measurement of low flows of liquids and gases. Their main application field is in purging, analyzer and gas sampling systems, laboratories and machinery equipment.
Integrated needle valves are optionally available and are used for the fine adjustment of the flow. The special design of the RAGL makes it possible to replace its glass tube without removing the complete device from the installation.
These simple and affordable Rotameters have a very broad application range, large variety in cones and floats and decades of proven design.
The Rotameters RAGK and RAGL complete Yokogawa’s Metal and Glass Rotameter Portfolio suitable for SIL applications and applications complying to the Machinery Directive.



  • Suitable for applications according to IEC 61508:2010 and ISO 13849-1
  • Space-saving design
  • Needle valves for fine adjustment of flow
  • Negligible pressure loss
  • Cost-effective solution


Refer to the General Specification sheet located under the ‘Downloads’ tab for detailed specifications.

For Pipe Sizes 1/4 inch to 3/8 inch
Process Connections Threaded, Swagelok, cutting ring, nozzle
Measuring Range Water 20 °C: 2 ml/h – 600 l/h
Air 20 °C 1 bar abs.: 0.1 l/h – 6300 l/h
Wetted Parts Material Borosilicate glass, 1.4571 (AISI 316Ti) or Polypropylene
Various float materials available
Gaskets NBR, FKM, PTFE
Process Temperature -25 °C to + 130 °C
Process Pressure 16 bar
Ambient Temperature -25 °C to 80 °C
Measuring accuracy acc. VDI/VDE 3513 sheet 2 (qG=50 %) 1.6 % / 2.5 % / 4 % /
Hazardous Area Approvals ATEX, IECEx and NEPSI
Suitable for Applications acc. IEC 61508
and Machinery Directive ISO 13849-1
Additional Features Limit switches for low/high alarms
Fine control valves
Pressure controller