Seametrics TX80 Series - Manual (Page 2)

Installation
Fitting Installation. TX80 Series meters require spe-
cial fittings. The meter fitting must first be installed in the
pipeline. Straight pipe of at least ten times the diameter
upstream of the meter and five diameters downstream
are strongly recommended. Inadequate straight pipe,
especially downstream of an elbow, change in pipe di-
ameter, or partially-opened valves, can result in signifi-
cant inaccuracy. Typically this inaccuracy is in the form
of the meter reading "high". TX80 Series meter fittings
are supplied with some upstream straight pipe. In the
larger sizes, the length provided is less than ten diam-
eters upstream and five downstream. It is not advisable
to connect directly to the end of these fittings with a flow-
disturbing device such as a valve or elbow. If possible,
straight pipe should be added to these fittings.
A PVC fitting is usually installed by solvent welding. The
stainless steel and brass meter fittings have female pipe
threads, requiring the appropriate male threaded fittings.
Saddle fittings (size 3" and above) require a hole to be
cut in the pipe. The recommended hole size is 1-3/4".
!
Caution: Never remove the u-
clip retainer when the pipe is
under pressure. Always remove
pressure from the pipe before
attempting to remove the meter.
Removal under pressure may result in damage
or serious injury.
Meter Installation. After the meter fitting is installed in
the pipeline, the meter can be installed in the fitting. Press
the meter into the fitting as far as it will go. Then retain
the meter in place by inserting the u-pin. This pin
can be installed from either side. It is sometimes neces-
sary 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.
Meter Connection. See the “TX80 Series Connections”
diagram for meter connections. Unless the meter is sup-
plied pre-connected to a meter-mounted FT420 flow in-
dicator, three leads must be connected. These three
leads are color coded. The red wire is positive, the black
is negative, and the white wire is the signal lead.
Okay, if no air in pipe
Okay, if no sediment in
pipe.
TX80 Series Connections
Re d (+)
White (SIG)
Bla c k (-)
BEST
2 of 4
10 5
Diameters Diameters
K-factor. If the TX80 Series meter is ordered with its
fitting, the meter is factory calibrated in the fitting. A K-
factor (meter factor) is indicated on the side of the fitting.
This represents the actual number of pulses per gallon
the meter produced during the factory flow test. This
number can entered into an FT420 or FT520 flow indi-
cator to make it read properly. If a pulse divider is being
used, the K-factor is the starting point for calculating the
divider number.
These water meters are not recom-
mended for installation downstream of
the boiler feedwater pump where instal-
lation fault may expose the meter to
boiler pressure and temperature. Maxi-
mum recommended temperature is 130ºF (Plastic),
200ºF (Metal).
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