Rotameter – Variable Area Flowmeter

The Variable Area Flowmeter is one of the oldest and mature principles in flow measurement with its simple design: a float rises inside a conically shaped glass tube as the flow increases and its position on a scale can be read off as the flow rate. Since this measuring method is purely mechanic, it as simple as it is reliable.

RAGN

The RAGN Rotameter is designed for continuous flow measurement of liquids and gases. The borosilicate glass metering tube has a brightly colored easy to read scale. The RAGN comes standard with in-line 316 stainless steel fittings and optional stainless steel, titanium, PTFE or PVDF internals. Connection fittings for the RAGN can be chosen from NPT thread or Flanged connections.

The fluid passes through the metering tube from bottom to top so vertical installation is required. The actual flow is indicated by the top of the float and can be directly read from the scale on the metering tube.

RAMC

At first glance, the instrument looks impressive with its all stainless steel design. A closer look reveals a “float blockage” detection system. Operational safety is of the utmost importance in any flowmeter, and the RAMC is no exception – wetted parts are available in a variety of materials, and intrinsically safe outputs are available as an option.

If you value flexibility in a flowmeter – from the measurement of air to highly aggressive liquids – in situ replacement of the indicator without loss of performance – and the interchangeability of floats – then the RAMC is the right choice for you.

The RAMC combines all the advantages of the variable area principle with robust design, reliable measurement, with or without power, HART, culminating in a truly universal flowmeter for gases, liquids and steam applications.

RAKD

The small metal Rotameter RAKD differentiates itself from other comparable variable area meters by means of light and guided float design offering the smallest measurable flow ranges in the market. RAKD meters can be fitted with a fine control valve and are designed with horizontal process connections.

An integrated flow controller based on the differential pressure principle, which allows a constant flow rate to be maintained regardless of any variations in process pressure, is just one of the many different options available. The RAKD with either standard or fail safe limit switches is suitable for safety applications up to SIL level 2. The configuration with valve and controller reaches SIL level 1.

The RAKD Rotameter combines several benefits of the float principle: a robust design, reliable measurements, independence of the electrical power supply when operated as mechanical pointer instruments and an electrical output signal. They are moreover easy to install and require no maintenance. Both the RAMC and the RAKD are packaged in an attractive, all-stainless steel housing and boast a long service life under the harshest industrial conditions.

RAGK and RAGL

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.