Continuous Flow Measurement in Safety-Critical Applications

The new RAGN Glass Rotameter® from Yokogawa (Netherlands) is designed for the continuous flow measurement of liquids and gases in safety-critical applications where extended operating life and virtually maintenance-free operation are required.

With an FMEDA (Failure Modes, Effects & Diagnostics Analysis) report available for SIL (Safety Integrity Level) loop applications, the new unit has been assessed to SIL 1 according to the reworked IEC 61508:2010 standard and also complies with the Machinery Directive ISO 13849-1 standard.

The RAGN Glass Rotameter® resists highly corrosive media, comes in an all-stainless-steel housing, and offers measuring ranges from 2 ml/h to 10 m³/h of water and 0.1 l/h to 160 m³/h of air. The measuring glass tube is equipped with an easy-to-read scale highlighted by a yellow background and protected by a rotating splinter shield preventing glass splinters or aggressive media from escaping to the front in the event of glass breakage.

The modular design allows limit switches to be easily retrofitted to initiate minimum or maximum flow alarms when the magnetic float has reached or exceeded the limit switch position. Ease of wiring is ensured by an optional cable connection box which accommodates different process connections and sizes.

The mechanical design of the Rotameter® offers a number of benefits in terms of optimum productivity and reduced energy consumption. The relatively low pressure loss results in low pumping costs and energy savings. Moreover, Rotameters work without power, and under normal operating conditions they are maintenance free and have a virtually unlimited lifetime.

Yokogawa has placed great significance on the future sustainability of this product at every stage of the product lifecycle. The new RAGN can be completely disassembled and uses only recyclable materials only. The design also uses a large number of standard components from other Yokogawa flow products, leading to synergy in production and to resource and energy conservation.