Series HFO In-Line Flow Alarms

Latching Alarm Capabilities, For Air, Water or Caustic Fluids, Unrestricted Mounting

The Series HFO In-Line Flow Alarms provide continuous monitoring and control of flow rate levels. The flow alarm can be configured to open or close a contact for an increasing or decreasing set point. Available in 1/4", 1/2", 1" or 1-1/2" female NPT process connections, in aluminum, brass or 304 SS body.

California Residents:  Click Here for Proposition 65 WARNING.

Product Applications

  • Waste water processing
  • Lubrication systems
  • Process control
  • Solar systems
  • Drain lines
  • Pump testing

Models & Ordering

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Shipping Information

All shipping times are dependent on product availability at time of shipment.

Although we make every effort to ensure a continuous supply of our products, occasional circumstances may force us to temporarily run out of a product, or have shipping delays. Should this occur, customers will be notified soon after placement of any orders for such products and, if applicable, items will be put on backorder. For orders requiring expedited shipment, our customer service team can be contacted to confirm product availability

COVID-19 Update: Due to high customer demand, lead time on some products may be up to two weeks. While this is a developing health situation, we are working continuously to take the necessary measures to ensure that the products you need are available with minimal interruption.

Model Description Usually Ships* Price Code Order
Ships: 3-4 Weeks
Price: $585.00
In-line flow alarm, range 1.5-12 SCFM air, 1/4" female NPT. 3-4 Weeks* $585.00 N Order
Ships: 2-3 Weeks
Price: $585.00
In-line flow alarm, range 4-23 SCFM air, 1/4" female NPT. 2-3 Weeks* $585.00 N Order


Compatible gases or liquids.
Wetted Materials:
Body: Aluminum, brass or 304 SS; Seals: Buna-N or fluoroelastomer; Magnet: PTFE coated Alnico; Other internal parts: 304 SS.
500 SSU.
Temperature Limits:
170°F (76°C).
Pressure Limits:
Aluminum Body: 600 psig (41 bar); Brass body: 3500 psig (240 bar); 304 SS body: 6000 psig (413 bar).
Enclosure Rating:
NEMA 4X (IP66).
Accuracy Measuring:
±4% FS over entire range; ±2.5% over center third of the measuring range.
±1% of full scale.
Switch Type:
SPDT, 10A @ 250 VAC; 0.5A @ 125 VDC (resistive).
Shipping Weight:
1/4 to 1/2" female NPT models: 3 lb (1.4 kg); 3/4 to 1" female NPT models: 4.5 lb (2.0 kg); 1-1/2" female NPT models: 12 lb (5.4 kg).


  • Provides two 10 A SPDT limit switches with field adjustable alarm settings for application control and integral direct reading scale provides local indication of flow rate
  • Increased application versatility with no inlet or outlet straight plumbing requirement and can be mounted horizontally, vertically, or inverted
  • Outdoor or harsh environment installation capable with rugged cast aluminum construction and NEMA 4X (IP65) enclosure

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