Page 9
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Positioning the Meter
These meters can be installed horizontally, vertically (with
upward flow), or in any radial position.
Using a check
valve on the upstream side of the meter, and/or an air
vent (vacuum relief valve) in the same,
unobstructed run of pipe as the meter, is required in
any installation where the meter may be exposed to
suction when the system is not in normal operation.
Suction can cause damage to the liner. Liner damage
caused by suction, without the use of a check valve
and/or air vent, may void the warranty.
Straight Pipe Recommendations.
The
FMG470
Series
requires straight pipe before and after the meter
for best accuracy. However, the ability of electromagnetic
meters to average
the flow across the entire pipe allows for
shorter straight pipe
recommendations than most
mechanical meters (see page 7).
Full Pipe Recommendations.
To prevent false readings,
this meter is designed to indicate ‘EMPTY PIPE’ if one or
more electrodes is exposed. For highest accuracy, install the
meter so that the pipe will be full when there is flow. If air
bubbles may be present in the pipe or sludge accumulation
is an issue, rotate the meter by one flange hole to position
the control housing at a 45˚ angle (see diagrams on page
8).
Fittings.
The
FMG470 Series
has ANSI 150 lb. drilled
flanges and will mate with any other ANSI 150 lb. flanges.
See table on
page 10 for flange bolt tightening torque
specifications.
Calibration.
The
FMG470
Series
is factory-
calibrated before shipping. The frequency of
recalibration will depend on the needs of each application
and local regulatory policies.
Chemical Injection.
When the
FMG470 Series
is used in a
chemical injection application, the chemical injection
point must be placed downstream of the magmeter
OR far enough
upstream for complete mixing to
occur before the fluid
reaches the meter. When unmixed
chemical alternates with water passing through the
meter, the rapid changes in conductivity may cause
sudden spikes and drops in the meter’s reading,
resulting in inaccurate measurement. The
magmeter will
re-stabilize, however, with a steady flow of fluid of
uniform conductivity.
CAUTION:
These flow sensors are not
recommended where installation may
expose the flow sensor to boiler pressure
and temperature. Maximum recommended
operating temperature is 140˚ F.
CAUTION:
In chemical injection applications,
install chemical injection point downstream
of magmeter, or far enough upstream to
allow complete mixing of fluids.
INSTALLATION
Installing Gaskets
1. Be sure all mating surfaces are smooth and free of
debris.
2. Install Seametrics provided gaskets, or equivalent,
on each end of meter as shown in diagrams below.
If using grounding rings, install one gasket on each
side of the grounding ring.
3. Failure to install gaskets will void warranty.
Installation
without
grounding rings
Installation
with
grounding rings
GASKETS
Gaskets are required at all
junctions.
Gaskets
Gaskets
Grounding
Rings
FMG470 Series