Fluid Components International GF90_GF92 - Manual (Page 76)

FLUID COMPONENTS INTERNATIONAL LLC http://www.fluidcomponents.com
GF Series Flow Meter Models GF90/GF92 72 Doc. No. 06EN003229 Rev. H
1212.7 ACFM 19.7 PSIA 530 °R
1 580°R 14.7 PSIA
( )
=1485 SCFM
( ) ( )
Q
S
= Q
A
X
P
A
T
A
X
T
S
P
S
Verify Proper Orientation
The flow element must be oriented as described on the "Instrument Information Sheet" located in the
back of this manual. Verify that the flat on the flow element is parallel to the pipe and the flow arrow is
pointed in the direction of the flow stream. Improper orientation will cause an indeterminate amount of
error in the flow measurement. See Chapter 3 for instructions on proper installation.
Verify Proper Insertion Depth
The flow element's thermowells must be located at the center line of the pipe unless the factory specifies
otherwise. Improper insertion depth will cause an indeterminate amount of error in the flow
measurement. See Chapter 3 for instructions on proper installation.
Verify Standard versus Actual Process Conditions
The flowmeter measures the mass flow rate. The mass flow rate is the mass of the gas flowing through a
pipe per time. Other flowmeters, such as an orifice plate or a pitot tube, measure the volumetric flow rate.
The volumetric flow rate is the volume of gas per time. If the readings displayed by the GF series
flowmeters do not agree with another instrument, some calculations may be necessary before comparing
them. To calculate the mass flow rate, the volumetric flow rate, and the pressure and temperature at the
point of measurement must be known. Use the following equation to calculate the mass flow rate
(standard volumetric flow rate) for the other instrument.
Equation:
Where:
Q
A
= Volumetric Flow Q
S
= Standard Volumetric Flow
P
A
= Actual Pressure T
A
= Actual Temperature
P
S
= Standard Pressure T
S
= Standard Temperature
Pressure and Temperature are in absolute units.
In-Depth
Troubleshooting
The Installation
In-Depth
Troubleshooting
The Process
Example:
Q
A
= 1212.7 ACFM Q
S
= 1485 SCFM
P
A
= 19.7 PSIA T
A
= 120°F (580°R)
P
S
= 14.7 PSIA T
S
= 70°F (530°R)
NOTE: The rated outputs of fans, blowers or compressors cannot be accurately compared to the
flow rate output of the GF series flowmeter.
Swirling Flow and the Length of the Meter Section
The GF series flowmeter is calibrated in a non-rotating flow stream with the streamline parallel to the pipe
walls. Rotation of the flow stream or a flow stream that is not parallel to the pipe walls may cause flow
measurement errors. A straight pipe run of 20 pipe diameters upstream and 10 pipe diameters
downstream generally produces a desirable flow stream. Elbows, valves, and other obstructions,
located close to the GF Series Flowmeter may cause an indeterminate error in the flow rate measurement.
If a shorter pipe run distance is needed, a flow conditioner can be installed with the flow element.
Contact an FCI representative for more information.