FQB3 Mass Flow Controller

FQB3 Mass Flow Controller

The FQB3 is an electronic mass flow controller that incorporates an integral mechanical flow amplifier to produce flow rates up to 30 SCFM. From the factory, the FQB3 mass flow controller is married to an F-series high speed mass flow transducer. A set-point command to the FQB3 controller causes the electronic flow control circuit to open the mechanical flow amplifier until the mass flow rate of air detected by the F-series flow transducer matches the electronic set-point. The loop is always closed around the flow of air independent of the required pressures.

Accuracy ±
Repeatability ±
Max Flow (SCFM)
Max P1 (PSI)
  • Technical Specs
  • Downloads & Links
  • Request Quote

Technical Specs

Max Inlet Pressure150 PSI (10.34 Bar)
Accuracy±4% F.S.
Repeatability±0.25% F.S.
MIN/MAX Flow Range1 to 10 SCFM /3 to 30 SCFM
Port Size1/4″ NPT (BSPP Available)
DurabilityImmune to shock & vibration (up to 20 Gs)
Ambient Temps32-158°F (0-70°C)
Media Temps32-122°F (0-50°C)
Turn-Down Ratio10:1 (inquire about 20:1)
Filtration40 Micron
Power Requirement17-24 VDC

Request Quote

FQB3 Mass Flow Controller

The FQB3 mass flow controller is a compressed gas flow control assembly. The assembly consists of an FQB3-Series proportional control valve and an F-Series high speed flow monitor. The FQB3 mass flow valve consists of two normally closed solenoid valves, an integrated volume booster, a control circuit board and a protective canister.

The FQB3 operates by comparing the user’s electronic command input signal to the signal being returned to the FQB3 from the F-Series flow monitor. The on-board control circuit examines any differences between these signals and actuates the solenoid valves in response. Opening one solenoid valve removes compressed gas while opening the other solenoid valve adds compressed gas from the supply. The FQB3 continuously monitors the user command and F-Series feedback signals to keep the assemblies flow rate at the desired point.

Three Flow Control Models

with subtle differences and important implications


FR | Requires a known and fixed regulated supply pressure to maintain calibration


FP | Compensates for fluctuations in inlet pressure (up to 50%) to maintain calibration


FA | Requires output port open to atmosphere. Most commonly used in cylinder speed control.