Chemical Injection Or Fertigation; Fitting Installation; Meter Installation - Seametrics AG90 Series Manual

GENERAL INFORMATION

Fitting Installation

AG90-Series meters require special saddles that ensure
that the flow sensor is installed to the correct depth. The
saddle must be installed in the pipeline before the meter
can be installed. For best results, see straight pipe and full
pipe information on pages 8 and 9.
If there is not enough straight run to smooth out the
turbulence caused by valves, fittings, and changes in
direction, some decrease in accuracy may result. This does
not mean that the flow meter's reading is meaningless
however. In some applications (control systems, valve
operation, chemical addition) a repeatable reading may
be more important than a highly accurate one.
FLOW
Upstream straight pipe is selected during initial setup.
Upstream options are 5X or 10X the diameter and
are based on the amount of straight pipe available in
either new or propeller meter replacement installation.
Downstream straight pipe requirement is 2X the diameter.
See programming setup on page 14 for details.
.

Meter Installation

After the saddle is installed in the pipeline, the meter can
be installed in the fitting. After noting the direction of the
flow arrow, press the meter into the fitting as far as it will
go. Retain the meter in place by inserting the U-clip. The
pin can be installed from either side. It may be necessary
to rotate the probe back and forth slightly to start the pin
into the slots on the probe. Slide the pin in as far as it will
go.
NOTE: Install U-clip security seal if regulations require.
Seametrics • 253.872.0284
10X/5X
2X
Side (3 o'clock), top (12 o'clock) installations are acceptable.
Orienting the Meter
Flow Straightening Vanes/Conditioners
1. If you have the bolt-in, 3-vane style they may be removed
or left in place. They do not affect performance.
2. If you have the 6-vane, bolt-in style with a cone, it should
be removed.
3. For 6-vane, weld-in style installed in a spool, turn the
spool 180° and reinstall with the vanes behind the meter.
4. Orifice, tube or Vortab style conditioners will not affect
performance.

Chemical Injection or Fertigation

When any magmeter, by any manufacturer, is used in a
chemical injection application (including fertigation), 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 or fertilizer 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: In chemical injection or
fertigation applications, install chemical
injection point downstream of magmeter,
or far enough upstream to allow complete
mixing of fluids before the meter.
Page 6
AG90 - SERIES INSTRUCTIONS
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