McDonnel & Miller is pleased to introduce new General-Purpose Liquid Flow Switches, the Series FS250: Model FS251 (NEMA1 version) and Model FS254 (NEMA4 version).  This is the first new flow switch added to the McDonnel & Miller product line in over 20 years and incorporates key changes to address the needs of the market.

Key features of these patent pending flow switches include:

• Common switching mechanism for both the FS251 and FS254
  • Flow detection via stainless steel paddles inserted into flow stream piping
  • Brass body, paddle arm and pivot shaft
  • EPDM O-ring seals on the pivot shaft for long-life and durability in multiple chemical environments
  • Cam actuation of electrical switch
  • Easily accessible electrical connections and flow sensing adjustment screws
• Measured flow-rate sensing of 5.8 gpm in 1" pipe (2.2 fps) in horizontal pipe installations, which is 18% lower than measured flow of comparable general purpose flow switches from major competitors.
• 1-inch NPTM brass pipe connection
• Selection IV boiler ratings of 250% F and 160 psig
• No lead construction
• Housing materials:
  • FS251 - stamped sheet steel base with glass reinforced polycarbonate cover (similar to current FS4-3)
  • FS254 - cast aluminum base and cover

View the McDONNELL & MILLER SPEC SHEET for additional information.