Series HF In-Line Flow Monitors

For Air, Water or Caustic Fluids, ±2% FS, Unrestricted Mounting, High Temperature and Pressure Options

The Series HF In-Line Flow Monitors are ruggedly constructed and ideal for direct measurement for a range of compatible gases, oil or water based liquids. This Series is designed based on a floating orifice disk and variable area flow measurement. Flowing media forces linear motion of the orifice disk and a ring shaped magnet which ride on a tapered center shaft. The transfer magnet drives a clearly visible magnet follower located outside the flow tube, and a ring on the magnet follower indicates flow rate on the direct reading scale.

Note: If you require a calibration certificate with your flowmeter, please contact customer service to place your order.

California Residents:  Click Here for Proposition 65 WARNING.

Product Applications

  • Setting pressure relief valves
  • Fluid handling equipment
  • Detecting low-flow rates for lubricating liquids
  • Pulp and paper
  • Industrial maintenance
  • Fluid power
  • Heating loop flow

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

Build Your Custom Part. Use our Product Configurator

Model Description Usually Ships* Price Code Order
Ships: 2-3 Weeks
Price: $286.00
In-line flow monitor, 1/2" female NPT, 0.5-5 GPM (1-19 LPM) oil. 2-3 Weeks* $286.00 N Order
Ships: 2-3 Weeks
Price: $428.00
In-line flow monitor, 1" female NPT, 2-25 GPM (7.5-95 LPM) oil. 2-3 Weeks* $428.00 N Order

Can't find what you need? Build Your Custom Part. Use our Product Configurator


Compatible gases or liquids.
Wetted Materials:
HFA: Aluminum casing, Buna-N seals, PTFE coated Alnico magnet, SS disk; HFB: Brass casing, Buna-N seals, PTFE coated Alnico magnet, SS disk; HFS: 303 SS casing, FKM seals with PTFE backup, PTFE coated Alnico magnet, SS disk.
Maximum Viscosity:
500 SSU.
Temperature Limits:
240°F (116°C).
Pressure Limits:
HFA, HFB, HFL and HFH models: 600 psig (41 bar) for air and gas, 3500 psig (241 bar) for liquids;
HFS model: 1000 psig (70 bar) for air and gas, 6000 psig (413 bar) for liquids.
±4% FS over entire range; ±2.5% over center third of the measuring range.
±1% of FS.
Shipping Weight:
1/4" to 1/2" female NPT models; 2 lb (0.9 kg);
3/4" to 1" female NPT models: 3.5 lb (1.59 kg); 1-1/2" female NPT models: 11 lb (5 kg);
2" female NPT models: 13.5 lb (6.12 kg).


  • This unique design allows accurate performance with fluid viscosities up to 500 SSU
  • All internal wetted parts are contained inside a sealed metal tubular casing assuring a virtually maintenance-free unit
  • Increased application versatility with no inlet or outlet straight plumbing requirement and can be mounted horizontally, vertically, or inverted
  • Rugged construction allows for high pressure and temperature rating for long operation life

Model Chart

EXAMPLE HF A 1 001 Series HFA-1-001 In-Line Flow Monitor, aluminum body, 1/4" female NPT dry seal, range 1.5-12 SCFM air.
SERIES HF       In-Line Flow Monitor
304 Stainless Steel
  1/4" Female NPT Dry Seal
3/8" Female NPT Dry Seal
1/2" Female NPT Dry Seal
3/4" Female NPT Dry Seal
1" Female NPT Dry Seal
1-1/4" Female NPT Dry Seal
1-1/2" Female NPT Dry Seal
RANGE       001
1.5-12 SCFM Air
4-23 SCFM Air
5-50 SCFM Air
10-100 SCFM Air
5-150 SCFM Air
30-330 SCFM Air
40-500 SCFM Air
150-900 SCFM Air

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