SUTO Flow Meters
Solutions/Monitoring/Flow Meters
Thermal Mass Flow

SUTO Flow Meters

Precision thermal mass flow measurement for compressed air and industrial gases. Configure your meter, build your part number, request a quote.

±1.5% accuracy
Multiple gas types
Modbus/4-20mA outputs
S401 Insertion Flow Meter
DN25-DN300
S401
For pipes DN25 to DN300 (1" to 12")

Insertion-style thermal mass flow meter for larger pipes. Install under pressure through a 1/2" ball valve without system shutdown. Shaft length automatically selected based on pipe diameter.

Install under pressure

Key Features

  • Install under pressure - no shutdown required
  • Pipe sizes DN25 to DN300 (1" to 12")
  • Automatic shaft length selection
  • Bi-directional flow measurement
  • Multiple gas calibrations available
Accuracy
±1.5% of reading + 0.3% FS
Turn-down
200:1
Pressure
Max 5.0 MPa
Protection
IP65
Configure S401
S421 Inline Flow Meter
DN15-DN80
S421
For pipes DN15 to DN80 (1/2" to 3")

Compact inline thermal mass flow meter with integrated measuring section. Easy installation with threaded or flanged connections. Available in 1.6 MPa and 4.0 MPa pressure ratings.

Integrated measuring section

Key Features

  • Compact inline design
  • Pipe sizes DN15 to DN80 (1/2" to 3")
  • Threaded or flanged connections
  • 1.6 MPa or 4.0 MPa pressure ratings
  • Exchangeable sensor unit
Accuracy
±1.5% of reading + 0.3% FS
Turn-down
200:1
Pressure
1.6 MPa or 4.0 MPa
Protection
IP65
Configure S421

Quick Comparison

Choose the right flow meter for your application

FeatureS401 InsertionS421 Inline
Pipe Size RangeDN25 - DN300 (1" - 12")DN15 - DN80 (1/2" - 3")
Installation TypeInsertion via 1/2" ball valveInline with measuring section
Install Under PressureYes - No shutdownNo - Requires shutdown
Pressure RatingUp to 5.0 MPa1.6 MPa or 4.0 MPa
Connection OptionsG1/2" (ball valve)R-thread, EN Flange, ANSI Flange
Best ForMain lines, large pipes, retrofitSub-metering, compact spaces
Configure S401Configure S421

How to Choose

Choose S401 if:

  • →Your pipe is larger than 3" (DN80)
  • →You need to install without shutting down the line
  • →You're measuring main distribution lines
  • →You need bi-directional flow measurement

Choose S421 if:

  • →Your pipe is 3" (DN80) or smaller
  • →You want the highest accuracy (integrated section)
  • →You're measuring machine-level or branch lines
  • →You need flanged or threaded connections