ITABAR Flow Sensor Type
FTMD
Operating manual
4. After the probe is fully retracted, the Flo-Tap
unit isolating valve {2} may closed for
complete disassembly.
7. Insulation
It is important for proper operation of the ITABAR
steam sensor that the phase change from vapour to
liquid take place only in the therefore specially
designed condensation vessels and not in the head
of the sensor.
Attention!
Do not insulate the condensation vessels.
The media in the differential pressure lines and
transmitter must be in a liquid state.
8.
Installation of valve block and
∆
p-transmitter
8.1. Valve
block
For steam measurement a 3-valve instrument
manifold is recommended. The valves of a 3-valves
manifold have the following functions:
• Valve C and D shutt-off to transmitter,
• Valve E Bypass valve (transmitter zero),
If a 5-vlave instrument manifold be used the value
has additiona function:
•
value F and G for drains
See Fig. 11
8.2.
∆
p-Transmitter:
For steam measurements, the differential pressure
transmitter should always be installed below the
ITABAR sensor in order to avoid the occurrence of
air bubbles in the instrument connections (see Fig.
11). Take care to mount the dp-transmitter exactly
horizontal, otherwise a small difference to
alignment is followed by a zero point error.
We recommend you to install the differential
pressure lines close together (connect hi and lo line
heat conducting) to maintain equal temperature.
Attention!
The differential pressure lines must have a min. inside
diameter from 10mm. Because the max. drop diameter
from water is 6,5mm.
(Prandl, L. "Führer durch Strömungslehre")
Fig. 11
9. Measurement
Start-Up
Make sure that:
- all installation openings are closed,
- all installed parts are securely bolted together,
- all shut-off valves are closed,
- close valve A and B for 15 minutes, so that
water can constitute in the condensate pots.
- all valves of 3- or 5-way manifold are closed.
- open valves A and B, after then all valves at the
3-way
manifold.
Attention: If a 5-way manifold valve are
mounted
valves F and G must be closed, because after
the
condensate steam penetrate and this can be
daugerous for personal.
- After 5 minutes, water will be constitute from
the lowest point to the condensate pots.
- close valves A and B and open vent valves C
and D, so air bubbles can escape.
- close valves C and D again, the transmitter must
show an 4 mA signal. By using a transmitter
with 0-20 mA output, it must be 0 mA.
- If the output signal from the transmitter is
more then 0 or 4 mA, the condensate pots don`t
have the same level.
- By difference, the transmitter must adjust to 0
or 4 mA.
- close valve E of the 3- or 5-way manifold. After
open valves A and B, the measuring are in
operation.
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