Dwyer Series DS In-Line Flow Sensors

Dwyer Series DS In-Line Flow Sensors

The Series DS In-Line Flow Sensors are two Series of averaging Pitot tubes for compatible gases and liquids that provide accurate and convenient flow rate sensing, for schedule 40 pipe, when purchased with suitable differential pressure gage with appropriate range. The Series DS-300 Averaging Flow Sensors are designed to be inserted in the pipeline through a compression fitting and available for pipe sizes from 1 to 10" (2.5 to 25.4 cm). Accessories include adapters with 1/4" SAE 45° flared ends compatible with hoses supplied with the Model A-471 Portable Capsuhelic® Gage Kit.

The Series DS-400 Averaging Flow Sensors are designed for insertion lengths up to 24" (61 cm) and include a pair of 1/8" NPT x 1/4" SAE 45° flared adapters which are compatible with hoses used in the Model A-471 Portable Capsuhelic® Gage Kit. The supplied solid brass mounting adapter has a 3/4" dia. compression fitting to lock in required insertion length and a 3/4" male NPT thread for mounting in a threaded branch connection (not included).


  • Multiple sensing point measurement and built-in averaging capability eliminates the need for “traversing” the flowing stream with single point velocity pressure measurement saving time
  • Extremely reliable, proven technology, Pitot tubes, have been used in flow measurement for years
  • All models include convenient and quick-acting quarter-turn ball valves to isolate the sensor for zeroing with 1/8" female NPT valve assembly process connections.
  • Furnished with instrument shut-off valves on both pressure connections with 1/8" female NPT connections rated at 200 psig (13.7 bar) and 200°F (93.3°C)
  • Where valves are not required, they can be omitted at reduced cost
  • The Series DS-400 Averaging Flow Sensors are quality constructed from extra strong 3/4" dia. stainless steel to resist increased forces encountered at higher flow rates with both air and water
  • Economical flow indication when used with appropriate differential pressure gage
  • Rugged construction yields, non-clogging, stable design


  • Remediation
  • Natural, flare, flue, stack gas
  • Boiler feedwater
  • Cooling water
  • Superheated, saturated, or geothermal steam
  • Combustion or compressed air
  • Oil flow monitoring


ServiceCompatible gases or liquids.
Wetted MaterialsSensor tube: 304 SS; Compression fitting: brass
Temperature Limit200°F (93.3°C).
Pressure Limit200 psig (13.78 bar) at 200°F (93.3°C).
Pipe SizesDS-300: 1 to 10˝ (2.5 to 25.4 cm); DS-400: 6 to 24˝ (15.2 to 61 cm)
Process ConnectionsDS-300: 1/4˝ male NPT compression fitting included; DS400: 3/4˝ male NPT compression fitting included.
Piping ConnectionsDS-300: 1/8˝ female NPT; optional 1/8˝ female NPT x 1/4˝ SAE 45 flared adapter sold separately; DS-400: 1/8˝ female NPT with 1/8˝ female NPT x 1/4˝ SAE 45 flared adapters include.
WeightsConsult factory

Download Data Sheet: Series DS In-Line Flow Sensors

Ref: dwyer-inst.com