High Capacity Indicators, Switches, Transmitters


  • Full scale flow ranges from 1 to 1200 GPM and 10 SCFH to 10,000 SCFM
  • Connection sizes from 1/4-inch to 8-inch NPT, BSP, flange, sanitary or victaulic
  • Construction materials: Brass, 316L S.S., Cast Iron, Aluminum, or Carbon Steel
  • Spring loaded, mechanical design mounts in any orientation
  • Easy to read, large scale design that rotates
  • Low pressure drop
  • Pressure ratings to 2000 PSIG
  • Optional field adjustable switches for hazardous and non-hazardous locations
  • Optional 4-20mA transmitter


Flow Network FM flow monitors combine flexibility, reliability, and quality for cost effective flow solutions in liquids, air, and gases. These flow instruments are field proven to be dependable, durable, and long lasting, even in the most difficult industrial applications. FM flow monitors provide direct reading indication of flow rate with optional electrical switches and transmitter outputs. Available in a variety of metal materials, these monitors are also offered in PVC and Teflon construction for corrosive fluids, or for use in corrosive environments.

FM flow monitors operate from two basic variable area spring loaded designs, the piston and vane styles. Both have a unique modular design for easy field installation and service. They do not require any straight pipe runs before or after the monitor thus minimizing the installation footprint. The versatile designs of the piston and vane style monitors allow for the piping orientation to be mounted in any position. Comparable to similar style devices in the industry, FM flow monitors “flow through” design offers a low-pressure loss. To ensure accuracy they are individually calibrated in any unit of measure to customer operating specifications. Piston style monitors operate when flow enters the inlet connection and forces the piston to create a variable orifice when moving across a tapered shaft. This movement drives the indicator shaft and pointer. On a loss of flow, the spring forces the piston back across the tapered shaft reducing the flow orifice created by the shaft and piston. Piston style monitors are used for monitoring maximum full-scale flows from 50 cc/min (.75 GPH) to 1.5 GPM. (See Series Y)

Vane style monitor operates when flow is introduced through the inlet connection making direct contact with the vane that is mechanically linked to the indicator shaft. The fluid forces the vane to move through a contoured opening creating a variable orifice. The greater the flow the larger the orifice becomes for flow to pass. The vane style monitor is also spring loaded and allows the vane to return on decreasing flows. Maximum full-scale flows are available from 1 GPM to1200 GPM. (See Series U, F, and M) For critical applications that require flow to be monitored, repeatable (1% of rate) field adjustable electrical switches are utilized. These switches are UL, CSA, and CE listed for hazardous and non-hazardous fluids, gases, or environments. For data collecting, trending, and recording applications output transmitters are also offered.


High Capacity Indicators, Switches, Transmitters