Liquid Controls LectroCount3, Руководство по установке

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10.2 INSTALLATION OF PIPE MOUNTED THERMOWELLS
Thermowells can also be installed in half
couplings that are welded in place on
the fluid line.
The two thermowells should be located
within 3” to 6” of each other and within 3
ft. of the meter inlet or outlet.
Avoid placing thermowells directly in
line, or a vortex may form behind the
first thermowell. This could affect the
temperature reading of the second
thermowell.
Both thermowell tips must point to the
center of the pipe.
A ½” NPT half coupling should be used
for the RTD stainless steel ½” NPT
thermowell.
The RTD well must be filled with the
copper, heat transfer grease (supplied).
The RTD must be positioned within 90
degrees of vertical. There must be
enough clearance to allow the RTD and
its electrical conduit to be installed, or
removed for service.
The stainless steel thermowell is used
for the 3-wire platinum RTD temperature
probe. Before inserting the probe into
the thermowell, thoroughly coat the
entire probe length with the copper, heat
transfer grease.
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Insert, then remove the probe from
the thermowell. Re-coat the end of
the RTD with the copper grease and
repeat the inserting/removal process
2 or 3 times. This will help make the
grease coating uniform inside the
thermowell, ensuring the heat
transfers from the liquid to the probe
inside the thermowell.
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The Thermowell Installation kit also
includes four foam washers and a
slotted metal disc.
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Slide the foam washers down the
RTD wires and position them at the
tail end of the RTD.
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Re-coat the RTD probe with the
grease and insert it into the
thermowell for the final time,
positioning it as far down in the
thermowell as possible.
The foam washers should “bottom out”
inside the Hex nut body of the
thermowell.
The disc should be positioned on top of
the foam washers, with the RTD wires
running through its slot.
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Next, feed the RTD wires through
the explosion proof union. Thread
the male ½" NPT side of the union
into the thermowell until the union
contacts the disc and compresses
the foam washers.
The washers can be added or
subtracted to provide an optimum fit.
The slotted disc will prevent the RTD
from being removed from the thermowell
without removing the union.
After attaching the conduit, the union
should be sealed with the seal wire kit.
10.2.1 For Canadian Installations
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A 3/8” NPT half coupling must be
welded in place to accommodate the
brass or stainless 3/8” NPT Weights
and Measures thermowell.
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The thermowell will be filled with a
light oil
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It needs to be positioned with 60
degrees of vertical to allow it to be
filled.
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Make sure that there is enough
clearance (typically 4 to 8 in.) to
allow the weights and measures
temperature probe to be inserted
and remove.