Flow Control

GF40

Brooks Instrument Series Elastomer-Sealed Gas Mass Flow Controllers and Meters

About this part

GF40 is Brooks Instrument’s series designation for GF040 elastomer-sealed digital thermal gas mass flow controllers and meters. MultiFlo-capable configurations can be reconfigured for supported gases and full-scale ranges. The bare GF40 identifier does not define the gas, calibrated range, valve, fitting, seal compound, downstream condition, or communications interface; those details require the complete configured model code or nameplate

Configurations vary. Verify the exact unit before choosing a replacement.

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Key Facts

ManufacturerBrooks Instrument

Part numberGF40

Product familyGF40 Series

Device typeMass Flow Controller

Configuration statusConfiguration varies

Application classSemiconductor/high-purity gas delivery

CategoryFlow Control

Specifications

Identification

Official designation

GF40 Series; documented base-model code GF040

Function

Device types	Gas mass flow controller with valve or measure-only gas mass flow meter
Measurement principle	Thermal mass flow

Construction

Seal system

Elastomer-sealed platform

Configuration

MultiFlo capability

MultiFlo gas and range programmability is standard at series level; the ordering code distinguishes MultiFlo-capable and non-MultiFlo configurations

Performance

Full-scale flow range	3 sccm to 50 slm nitrogen equivalent across the GF40 Series
Flow accuracy	±1% of setpoint from 35–100% full scale; ±0.35% of full scale from 2–35% full scale
Repeatability and reproducibility	Less than ±0.2% of setpoint
Linearity	±0.5% of full scale, included in the accuracy specification
Control range	2–100% of full scale
Settling time	Normally closed valve: less than 1 second; normally open valve: less than 3 seconds, settling within 2% for the documented step tests
Valve shutdown	Less than 1% of full scale
Pressure coefficient	0.03% per psi from 0–50 psi with nitrogen
Attitude sensitivity	Less than 0.25% span change after a 90° orientation change and rezeroing, with nitrogen at 50 psi

Ratings

Operating temperature	5–50°C (41–122°F)
Maximum operating pressure	150 psig (10 bar)
Design proof pressure	4000 psig (275 bar); this is not the permissible operating pressure

Integrity

External leak integrity

1 × 10^-9 atm·cc/s helium

Mechanical

Valve options	Normally closed, normally open, or no valve for meter configurations
Surface finish	32 µin Ra

Materials

Primary wetted materials	316 stainless steel, Hastelloy C-22, 17-7 PH, and 430 stainless steel at series level
Sensor tube	Large-bore corrosion-resistant Hastelloy C-22 thermal sensor tube
Seal and valve-seat options	Viton, Buna, Kalrez, or EPDM; exact compound is configuration-specific

Interfaces

Documented communications options

RS-485, Profibus, DeviceNet, and EtherCAT, with configuration-dependent analog I/O

Compliance

Documented compliance

CE to EN 61326:2006, safe-area design to EN 61010-1, and RoHS

What Does GF40 Mean?

GF40 identifies the product series, while GF040 is Brooks’ documented base-model code. Neither value is a complete configured ordering code.

Segment	Field	Interpretation
GF40	Series identifier	Brooks Instrument GF40 Series of elastomer-sealed gas mass flow controllers and meters.
GF040	Base-model code	Elastomer-sealed base platform covering the documented range through 50 slpm.
Not supplied	Configuration fields	The bare identifier provides no codes for configurability, special application, valve, gas/range, fitting, downstream condition, seals, communications, customer special request, auto shutoff, or reference temperature.

Configuration Identification

Use the complete model code and calibration/nameplate data to establish a unit’s gas, full-scale range, valve arrangement, process fitting, downstream-pressure condition, elastomer compound, electrical interface, customer-specific option, auto-shutoff selection, and reference temperature.

Valve and Response Options

Controller response depends on the ordered valve arrangement.

Valve configuration	Ordering-code value	Documented settling time
Normally closed	C	Less than 1 second
Normally open	O	Less than 3 seconds
Meter, no valve	M	Measure-only configuration; controller settling-time claim does not apply

Differential Pressure by Flow Band

The data sheet specifies configuration-dependent differential-pressure ranges; high-density gases such as argon typically require an additional 10 psid.