Digital flow switch of the PFMC7-L series with IO-Link also detects very small leaks

The digital flow switch of the PFMC7-L series features a wide measurement range, enhances process safety through a flow ratio of 100:1 and bypass construction, and enables a high degree of automation thanks to IO-Link compatibility. (Photo: SMC Deutschland GmbH)

In numerous processes, the flow of dry air or nitrogen (N2) is monitored using flow switches: from applications with main and secondary lines connected to gas cylinders to painting applications in the automotive industry. The goal is to detect leaks as early as possible to ensure process safety and save energy. The digital flow switch from the PFMC7-L series by SMC enables particularly precise monitoring, and thanks to IO-Link, it is ideally suited for Industry 4.0. Additionally, it features a rotatable, three-color, two-line display for easy reading and enhances process safety through bypass construction.

Whether in the food, chemical, or pharmaceutical industries, in electronics, or in mechanical engineering: process engineers across industries rely on flow switches to monitor the flow of dry air or N2. Important factors include suitable measurement ranges with low measurement error, ease of handling, high process safety, and a high degree of automation. To meet these challenges, SMC offers a comprehensive solution with the PFMC7-L series. The specialist for pneumatic and electrical automation provides a digital flow switch with IO-Link, which features a particularly high flow rate through a bypass construction and offers an immediate overview of all important parameters via a three-color, two-line display.

Future-proof plant automation

To enable users to continuously prepare their plants for Industry 4.0, the PFMC7-L series is IO-Link compatible and equipped with an M8 connector. This allows data exchange via a standardized interface to read device data. Device settings can also be made remotely via fieldbus (e.g., ProfiNet) and an intermediate IO-Link master. Thanks to an embedded diagnostic bit in the cyclic (periodic) process data, device problems can be detected, and these can be monitored in detail with the acyclic (aperiodic) data. This allows immediate identification of errors such as measurements above or below the nominal flow range or the accumulated flow. This paves the way for predictive maintenance, resulting in higher process safety and cost reduction.

Measuring and recording

With a nominal flow range from a minimum of 5 to a maximum of 2000 l/min, flow measurements in particularly high ranges are no problem. The flow ratio of 100:1 ensures that even small leaks of 1% of the end value of the measurement range can be detected, positively impacting both process safety and energy consumption. The three-color, two-line display of the PFMC7-L series provides immediate information on setpoint, current flow rate, and cumulative values. It can be rotated 90° counterclockwise or 225° clockwise for better visibility and adapted to the actual piping. Additionally, the response time of the digital filter can be adjusted between 50 and 200 ms depending on the application — for IO-Link-compatible products, a value of 500 ms can also be selected.

Bypass extends lifespan

The MEMS sensor integrated into the PFMC7-L series for measuring volumetric flow reacts to humidity or suspended particles in the medium. To ensure reliable measurements over long periods and extend lifespan, SMC engineers equipped the digital flow switch with a bypass construction. This allows the chip to perform its primary function without being directly exposed to the main airflow. As a result, downtime is reduced, and users benefit from lower costs. Additionally, the series features an IP65 protection rating.