Technical Glossary

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Corrosion Resistant Fan/Blower

Gas Volume

The amount of air or gas intake in a particular time unit
m3/min、CMM:gas volume per1 minute
m3/h、CMH:gas volume per1 hour
m3/min、CFM:gas volume per min = cubic feet (used often in America)
          1f3/min=0.0283m3/min
Nm3/min:gas volume under normal conditions (0℃, humidity 0%, intake absolute pressure 760mmHg)
Convert into the gas temperature. Calculation is below


Qt:converted gas temperature t℃ gas volume
QN:requested gas volume under normal conditions

Static Pressure

mmAq:A unit shown in height when the water pumped in or up
Aq=Aqua (water) abbreviation. Waterspout in millimeters (written as mmH2O)

inH2O:If not in millimeters, written in inches. (used often in America)
1 inch=25.4mm

Pa:Pascal (International unit for measuring pressure)
1mmAq=9.80665Pa

kgf/m2:1kgf/m2=1mmAq

bar:bar (European unit for measuring pressure)
1bar=10.197mAq、1mbar=10.197mmAq

Shaft Power

The measure of power used at the shaft of the fan. Shaft power is measured in kW.

Revolution Speed

rpm、(R/M)、min-1:revolution per 1 minute

Gas Specific Weight

kg/m3:Weight per unit volume of gas
Generally1.2kg/m3 is most common under normal conditions (20℃, relative humidity 65%, and absolute pressures 760mmHg)

The specific weight of the gas changes due to temperature variations.
The change in the specific weight of the gas due to temperature is calculated as follows.



:Specific weight of gas at temperature t℃ of gas kg/m3
:Specific weight of gas in 0℃ temperature of gas kg/m3

Conversion affected in specific weight volume performance

All the performance labels in the fan catalog (capacity chart) are displayed by the normal atmospheric
conditions. Therefore, specific weight becomes 1.2kgf/m3.
Usually under general atmospheric condition there is no problem but when specific weight of the gas differs by
a large amount it is necessary to refer to the capacity range chart.
This conversion is calculated as follows

(1)Static Pressure


SSp=The actual static pressure found in a particular situation (static pressure required by the customer) mmAq
Sp':Static pressure as shown seen in capacity range chart mmAq
:The specific weight of the gas used

(2)Shaft Power


LB:Actual shaft power kW
LB':Shaft power as shown in the capacity range chart
:Specific weight of gas being used kg/m3

Conversion affected in rotation speed performance

The relation between the change in the blower rotational speed and the change in the gas volume, the static pressure, and the shaft power is proportional as follows.
(1)Gas Volume


(2)Static Pressure


(3)Shaft Power


N1:Rotation speed before change rpm
N2:Rotation speed after change rpm

Q1:Gas volume before change in rotational speed m3/min
Q2:Gas volume after change in rotational speed m3/min

Sp1:Static pressure before change in rotational speed mmAq
Sp2:Static pressure after change in rotational speed mmAq

LB1:Shaft power before change in rotational speed kW
LB2:Shaft power after change in rotational speed kW

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