User Manual
10
Actual Volumetric Flow Rate
1) To obtain actual volumetric flow rate at inlet
flowing
temperature
other than
70ºF,
find
the flow rate
(Q)
that corresponds to the corrected DP. Multiply Q
by
the viscosity correction only.
See chart A-31986 for corrections.
2) At
flowing
inlet
temperature
of 70ºF read curve
directly in actual volumetric flow rate.
Actual volumetric flow rate equals standard
volumetric
flow rate when flowing conditions are 70ºF
and 29.92" Hg.
Notify Meriam if your flowing gas is not air
and/or
standard conditions are different from 70ºF and
29.92"
Hg
absolute. A special curve/table can be provided list
ing
the gas being flowed. The gas
viscosity
correction, µstd / µf
will
reference
the gas and/or new
standard temperature value
,
if
applicable. Table
A-32422 or
A-31986 cannot be used for gases other than air.
Gas Flow Other Than Air/Standard Conditions From 70°F and 29.92” Hg ABS.
Select the proper flow
curve/table
for the LFE
being
used.
Standard Volumetric Flow Rate
1)
To obtain standard
volumetric
flow rate if the
inlet
temperature and pressure are different from
standard,
read the flow rate (Q) from the
curve/table corre
sponding to the corrected differential
pressure
(DP).
Calculate
the
viscosity
at the flowing
temperature
using the viscosity equation
for the flowing gas.
Then
calculate the viscosity correction factor (µcf)
using
µcf
=
Locate the
pressure correction
factor (Pcf) for
the
flowing
inlet
pressure
on chart
A-31031 or
calculate the correction factor
using
Pcf =
Locate the temperature correction factor (Tcf)
for
the
flowing temperature
on chart
A-35700
or
calculate
using
Tcf =
Multiply Q from the curve/table by the viscosity
cor
rection factor (µcf), the pressure correction factor
(Pcf)
and the temperature correction factor (Tcf).
This
product
will give the flow rate of a particular
gas at the
standard conditions.
2)
At flowing inlet conditions equal to the standard conditions
,
read curve/table directly in standard
volumetric flow
rate.