QIYUE FAN / Boiler Forced Draft Fan Family
Boiler Forced Draft Fans
Compare centrifugal forced draft fan directions for boiler combustion-air supply, burner pressure and higher-resistance air-side systems. Final selection should be based on the complete combustion-air route rather than boiler capacity or motor power alone.
Primary Function
Combustion Air Supply
Before burner or furnace
Product Map
5 Core + 2 Extended
Boiler + high-pressure directions
Selection Basis
Airflow + Pressure
Complete air-side resistance
Project Types
New & Replacement
System design or interface matching
On This Page
Selection Focus
Combustion Airflow
Total Pressure
Air Temperature
Burner Demand
Combustion Airflow
Total Pressure
Air Temperature
Burner Demand
01 / Product Family Positioning
Select the Fan from the Complete Combustion-Air Route
A boiler forced draft fan should not be selected from motor power or boiler capacity alone. The required combustion-air volume, total air-side resistance, inlet temperature, burner demand and operating range should be confirmed before choosing the fan series.
The fan must provide enough airflow and pressure to overcome the resistance of the complete clean-air route before the burner or furnace.
01 / BOILER
Boiler and Fuel
Confirm boiler capacity, fuel, firing rate, burner type and maximum operating load.
02 / AIRFLOW
Combustion Airflow
Use the confirmed maximum combustion-air demand and required operating range.
03 / PRESSURE
Air-Side Resistance
Include intake, filter, silencer, damper, duct, air-preheater and burner losses.
04 / CONFIGURATION
Control and Layout
Confirm damper or VFD control, rotation, outlet angle, motor standard and foundation.
02 / Direct Product Entry
Boiler Forced Draft Fan Product Series
Start with the five core boiler forced-draft directions below, including the G4-68 clean-air forced-draft series. If the required operating point moves toward higher pressure or heavier forced-air duty, continue to the 9-26 and 8-09 extended directions.
G4-68
CLEAN-AIR BOILER FD
G4-68 Boiler Centrifugal Forced Draft Fan
Clean-air forced-draft direction for boiler combustion-air supply and industrial positive-pressure air systems. Select it from the required airflow, pressure and complete air-side resistance rather than from the ordinary 4-68 ventilation model name alone.
Selection focus: combustion airflow · total air-side pressure · inlet temperature · motor and installation arrangement.
View G4-68 → 
G4-73
LARGE BOILER CLEAN-AIR SIDE
G4-73 Boiler Forced Draft Fan
Clean-air-side direction for medium and large steam boiler combustion-air supply.
Reference direction: 2–670 t/h boilers · inlet air normally up to 80°C.
View G4-73 → 
GY5-51
POWER & FLUIDIZED-BED DUTY
GY5-51 Boiler Draft Fan
Forced-draft direction for steam boilers and higher-pressure fluidized-bed combustion-air systems.
Reference direction: 2–670 t/h boiler systems · D-type coupling structure.
View GY5-51 → 
G6-41
SMALL & MEDIUM BOILER ROOM
G6-41 Boiler Blower
Compact combustion-air blower direction for small and medium industrial boiler rooms.
Reference direction: 0.5–10 t/h industrial boilers · A- or D-type drive.
View G6-41 → 
9-19
HIGHER-RESISTANCE AIR SUPPLY
9-19 High Pressure Centrifugal Fan
Pressure-oriented direction for boiler forced draft, combustion support and other higher-resistance air systems.
Selection focus: fan curve, system resistance, drive arrangement and motor capacity.
View 9-19 → Additional High-Pressure FD Fan Directions
For More Demanding Combustion-Air Duties
These series are not general boiler-fan substitutes. Review them when the required airflow-pressure operating point extends beyond the normal boiler forced-draft directions.
9-26
HIGHER AIRFLOW + PRESSURE
9-26 High Pressure Centrifugal Fan
For larger-airflow, higher-pressure forced-air duties where the system includes significant duct, equipment, damper or process resistance.
Review when: airflow demand increases while substantial pressure is still required.
View 9-26 → 8-09
FURNACE BLOWING · HIGH PRESSURE
8-09 High Pressure Centrifugal Fan
High-pressure fan direction for cupola furnace blowing, melting furnace air supply, forging furnace ventilation and other pressure-oriented combustion-air duties.
Reference range: 675–6,049 m³/h · 10,523–20,736 Pa.
View 8-09 → Need a Different High-Pressure Operating Region?
The wider high-pressure centrifugal fan family covers additional airflow and pressure regions without turning this boiler FD page into a duplicate high-pressure fan catalog.
Compare High-Pressure Centrifugal Fans → Model note: boiler forced-draft selection should still begin with the actual clean-air operating point. High-pressure centrifugal series are extensions for suitable airflow-pressure regions, not automatic replacements for dedicated boiler fan series.
03 / Combustion-Air System Route
Where the Forced Draft Fan Works
The FD fan pushes ambient or preheated combustion air toward the burner and furnace. Pressure selection should include every air-side component before the combustion zone.
STEP 01
Air Intake
Ambient air, intake hood or preheated-air return route.
STEP 02
Filter / Silencer
Inlet restriction, filtration and sound-control resistance.
STEP 03
FD Fan
Supplies airflow and pressure to the combustion-air system.
STEP 04
Preheater / Damper
Heat-recovery resistance and airflow-control losses.
STEP 05
Burner / Furnace
Terminal pressure demand and combustion-air distribution.
04 / Preliminary Comparison
Which FD Fan Direction Should Be Reviewed First?
This comparison is a product-navigation tool. It does not replace final fan-curve checking or technical selection.
SERIES
POSITION
TYPICAL DIRECTION
PRIMARY CHECK
G6-41
Small / medium boiler
Compact combustion air
Airflow + boiler duty
G4-68
Boiler clean-air FD
Combustion-air supply
Airflow + pressure + resistance
G4-73
Medium / large boiler
Large airflow clean-air side
Duty + air temperature
GY5-51
Boiler / fluidized-bed
Broader pressure duty
Operating point + role
9-19
Pressure-first
High-resistance forced air
Pressure + fan curve
9-26
Airflow + pressure
Heavy forced-air duty
Curve + motor load
8-09
Small-flow high pressure
Furnace blowing
Airflow + high pressure
Selection note: calculate the required pressure at the maximum confirmed combustion airflow. Extra pressure margin should be project-based; oversizing can create unnecessary energy use and poor control at lower boiler load.
05 / System Relationship
Forced Draft Fan vs. Induced Draft Fan
FD and ID fans work on different sides of the boiler. Their medium conditions, pressure routes and selection risks are therefore different.
SELECTION POINT
FORCED DRAFT FAN
INDUCED DRAFT FAN
System Position
Before burner or furnace
After boiler or dust-removal equipment
Main Function
Supplies combustion air
Extracts flue gas and supports negative pressure
Typical Medium
Ambient or preheated clean air
Hot flue gas, ash, moisture or treated exhaust
Pressure Route
Intake, filter, damper, preheater and burner loss
Boiler, collector, scrubber, duct and chimney loss
Primary Risk
Insufficient air or excessive furnace pressure
Temperature, dust, corrosion and draft instability
06 / Project Type
New Boiler Projects and Replacement Fan Projects Need Different Inputs
NEW BOILER PROJECTS
Design from the Maximum Combustion-Air Duty
Define the maximum firing condition and calculate pressure loss through every air-side component before selecting the fan.
Boiler capacity, fuel and burner type
Maximum combustion-air volume
Required static or total pressure
Intake, filter and silencer resistance
Air-preheater and burner-register loss
Control method, altitude and power supply
REPLACEMENT FAN PROJECTS
Match the Interface and Correct the Air-Supply Problem
Current operating performance and connection dimensions are as important as the original fan model.
Existing fan and motor nameplates
Current airflow, pressure, speed and power
Inlet, outlet and foundation dimensions
Rotation and discharge angle
Low air, overload, noise or unstable pressure
Site photos, drawings and available space
07 / Configuration Review
Configuration Must Match the Boiler Air Side
Drive Arrangement
A-, D- or another supported drive arrangement is selected according to model size, speed, motor layout and maintenance access.
Inlet Air Temperature
State whether the fan handles ambient air or preheated combustion air. Temperature affects density, performance and motor load.
Damper or VFD Control
Control method should match the boiler load range, low-load operation and required pressure stability.
Rotation and Outlet Angle
Left- or right-hand rotation and discharge angle must match the actual duct direction.
Motor & Electrical Standard
Provide voltage, frequency, phase, enclosure, insulation, starting method and project-specific efficiency requirements.
Connection & Foundation
For replacements, send inlet, outlet, base and shaft-center dimensions. A measured drawing reduces installation risk.
08 / Typical Applications
Typical Boiler Forced Draft Applications
APPLICATION 01
Industrial Steam Boilers
Combustion-air supply for factory boiler rooms and process-steam systems.
APPLICATION 02
Biomass & Coal Boilers
Primary or combustion-air support subject to fuel, burner and furnace requirements.
APPLICATION 03
Fluidized-Bed Boilers
Higher-pressure combustion-air systems requiring operating-point confirmation.
APPLICATION 04
Furnaces & Burners
Forced combustion or process-air delivery for furnace and burner systems.
09 / What to Send
Boiler FD Fan Selection Information
Provide the actual operating point and boiler air-side conditions whenever possible.
01
Boiler Capacity
Boiler capacity, fuel and burner type.
02
Combustion Airflow
Normal and maximum combustion-air demand.
03
Required Pressure
Required static or total pressure at the confirmed airflow.
04
Inlet Temperature
Ambient air or preheated combustion-air temperature.
05
Air-Side Resistance
Filter, silencer, duct, damper, air-preheater and burner losses.
06
Control Method
Damper control, VFD control and expected load range.
07
Electrical Data
Voltage, frequency, phase and motor requirements.
08
Replacement Data
Nameplate, dimensions, rotation, outlet angle, site photos and current problem.
Continue the Selection Path
Related Boiler Fan Pages
10 / Technical FAQ
Boiler Forced Draft Fan Questions
What is the function of a boiler forced draft fan?
It supplies combustion air to the burner or furnace and provides enough pressure to overcome the resistance of the complete air-supply route.
Can the fan be selected only from boiler capacity?
No. Boiler capacity gives an initial direction, but final selection requires combustion airflow, total pressure, air temperature, burner demand, control method and installation data.
What pressure losses should be included?
Include intake, weather hood, filter, silencer, damper, duct friction, elbows, air preheater, burner register and terminal-entry resistance.
When should 9-19 or 9-26 be reviewed?
Review these high-pressure centrifugal directions when the required operating point involves greater system resistance than a normal boiler forced-draft duty. Final selection still requires fan-curve and motor-load confirmation.
Where does the 8-09 series fit?
8-09 is a high-pressure direction for furnace blowing and other pressure-oriented combustion-air duties. It should not be treated as a general substitute for every boiler forced-draft fan.
What should be sent for a replacement FD fan?
Send fan and motor nameplates, airflow, pressure, speed, motor power, inlet and outlet dimensions, foundation dimensions, rotation, outlet angle, site photos and the current operating problem.
Boiler FD Fan Selection
Send Your Boiler Forced Draft Fan Operating Point.
Boiler Capacity · Fuel · Burner Type · Combustion Airflow · Total Pressure · Air Temperature · Air-Side Resistance · Control Method · Power Supply · Quantity
Manager Zhao
SHANDONG QIYUE FAN CO., LTD.
Industrial fan selection and export project support
Tel / WeChat / WhatsApp: +86 15653305981
Email: sales@qiyuefan.com
Factory: Dongchen Industrial Park, Zhoucun District, Zibo, Shandong, China
Email: sales@qiyuefan.com
Factory: Dongchen Industrial Park, Zhoucun District, Zibo, Shandong, China
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