FMG490 INSTRUCTIONS
Page 10
Positioning the Meter
These meters can be installed horizontally, vertically (with
upward flow), and 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 FMG490 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 8).
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 9).
Fittings.
The meters have ANSI 150 lb. drilled flanges and
will mate with any other ANSI 150 lb. flanges.
See table
on page 11 for flange bolt tightening torque specifications.
Calibration.
The FMG490 meters are factory-calibrated
and will not require any form of field calibration.
Chemical Injection.
When an FMG490 meter 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 restabilize, 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 130˚ 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 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
