CDI 6400 for 2″ – 8″ pipes

Price Range: $695 – $2,245

Although our initial ruggedized flowmeter is still available for purchase, we now offer the CDI 5000 Series flowmeters with the same great features and the option for wireless monitoring.

The flowmeter clamps onto a pipe, with two flowsensing probes projecting into the pipe through 3/16 in. drilled holes. It seals directly to the pipe; no cutting or welding is required for installation. Because each flowmeter is made and calibrated for a specific size of pipe, the display indicates flow directly, with no setup or adjustment.




  • Easy to install
  • Housing and display rotate to suit piping orientation
  • IP-66 rating; suitable for wet locations
  • Milliamp and pulse outputs
  • Optional RS-485 output for networking

The CDI 6400 is similar to the CDI 6200, except that it has its probes mounted side-by-side in a single ring and it is built for larger pipe sizes. Like the 6200 and the 5000-series meters, it is a thermal mass flow meter in which one probe senses the air temperature and the other is maintained ten degrees above the air temperature. It has the same milliamp and pulse outputs, the same large, bright display, and an optional Modbus RS485 output for networking.

Additional information

Number of Rings

1 Ring

Material Type

, ,

Nominal Pipe Sizes

2 in. – 8 in., 50 mm – 101 mm, DN50 – DN200


5 percent of reading plus one percent of full scale at an air temperatures from 20 to 120 degrees Fahrenheit (-6.5 to 49 Celsius) and a pressure of 100 psig (7 bar).


Compressed Air, Nitrogen

Operating Pressure

200 psig (14 bar) maximum on Sch. 40 steel and on Type L copper below three inch; consult CDI for other materials and sizes.

Input Power

250 mA at 20 to 28 Vdc

Output Resistance

600 Ohms max.

Exposed Materials

Stainless steel, gold, thermal epoxy and Viton (seal)

Ring Material



Four digit LED display

Response Time

One second to 63 percent of final value



Model No Nominal Pipe Size Range (scfm) Price
6400-20C, 6400-20S 2.0 in. (DN50) 600 $695
6400-25C, 6400-25S 2.5 in. (DN65) 800 $845
6400-30C, 6400-30S 3.0 in. (DN80) 1200 $1,045
6400-40C, 6400-40S 4.0 in. (DN100) 2000 $1,345
6400-50S 5.0 in. (DN125) 3000 $1,845
6400-60S 6.0 in. (DN150) 5000 $1,845
6400-80S 8.0 in. (DN200) 6000 $2,245
6400-50M 50 mm 600 $695
6400-63M 63 mm 800 $895
6400-76M 76 mm 800 $1,045
6400-101M 101 mm 2000 $1,345

Note: Flowmeters for 3″ and 4″ copper have lower flow ranges and full scales than their steel counterparts.
* Note: A wall plug power supply modification is available.


Click the files below to download.

CDI 6000 Series Quickstart

CDI 6400 Datasheet

CDI 6400 Instructions

CDI 6400 Shop Drawing

CDI Flowmeter Ranges

CDI Units of Measure Explanation

CDI Flowmeter Wiring

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