Fluid Components International ST51A and ST75A thermal mass flow meters

Process and plant engineers with operations or subsystems that require IEC 61508 compliance can look to the ST51A and ST75A thermal mass flow meters from Fluid Components International (FCI) for air/gas flow measurement. The compact thermal flow meters have been evaluated by safety expert Exida and found to meet SIL 1 compliance.

The ST51A flow meter is an insertion-style instrument designed for use in pipe diameters larger than 51 mm. It is optimised for flow measurement of air, compressed air, nitrogen, natural gas, digester gas and all other biogases.

The ST75A flow meter is an inline-style instrument designed for use in pipe diameters from 6 to 51 mm.  The meter is designed for applications in air, all inert gases, natural gas and other hydrocarbon gases.

Both models feature wide 100:1 turndown, good IP67 dust/water ingress protection and rugged, all-metal enclosures. They carry global agency approvals for Div 1/Zone 1 Ex installations and have no moving parts.

For interface and communications, the instruments’ outputs include dual 4–20 mA and a 500 Hz pulse. Optionally available is a two-line LCD readout to display flow rate and either temperature or totalised flow.

The transmitter/electronics can be integrally mounted with the flow element or remote mounted up to 30 m away. Users have a choice of 24 VDC or 85 to 265 VAC powering. The transmitter enclosure is available in either painted aluminium or stainless steel and can be ordered with either NPT or metric threaded cable ports.

Both meters are temperature compensated and calibrated to the user’s actual installation conditions in one of FCI’s 19 flow stands using NIST and ISO/IEC 17025 traceable equipment. For applications with limited straight-run, they can be supplied with and calibrated specifically for use with Vortab Flow Conditioners.