Endress+Hauser Dosimag, Руководство по эксплуатации

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Installation Dosimag
22 Hauser
6.2.4 Welding the sensor into the pipe (welding connections)
L
WARNING
Risk of destroying the electronics!
‣
Make sure that the welding system is not grounded via the sensor or transmitter.
1. Tack-weld the sensor to secure it in the pipe. A suitable welding jig can be ordered
separately as an accessory →  69.
2. Release the screws on the process connection flange and remove the sensor, along
with the seal, from the pipe.
3. Weld the process connection into the pipe.
4. Reinstall the sensor in the pipe, and in doing so make sure that the seal is clean and
in the right position.
• If thin-walled pipes carrying food are welded correctly, the seal is not damaged by
the heat even when mounted. However, it is recommended to disassemble the
sensor and seal.
• It must be possible to open the pipe by approx. 8 mm (0.31 in).
6.2.5 Cleaning with pigs
It is essential to take the internal diameters of the measuring tube and process connection
into account when cleaning with pigs. All the dimensions and lengths of the sensor and
transmitter are provided in the separate "Technical Information" document.
6.2.6 Seals
When mounting the process connections, make sure that the seals in question are dry,
clean, undamaged and correctly centered.
• The screws must be firmly tightened. The process connection forms a metal
connection with the sensor, which ensures a defined compression of the seal.
• Depending on the application the seals should be replaced periodically, particularly
if molded seals are used (aseptic version)!
The interval between changes depends on the frequency of the cleaning cycles, the
cleaning temperature and the medium temperature.
Replacement seals can be ordered as an accessory.
6.2.7 Nominal diameter and flow
The diameter of the pipe and the flow rate determine the nominal diameter of the sensor.
The optimum flow velocity is between 1 to 4 m/s (3.28 to 13.12 ft/s). The velocity of flow
(v), moreover, has to be matched to the physical properties of the fluid:
• v < 2 m/s (6.56 ft/s): For abrasive media such as cleaning agents etc.
• v > 2 m/s (6.56 ft/s): For media that produce buildup, such as oil and liquids that
contain sugar
A necessary increase in the flow velocity can be achieved by reducing the sensor
nominal diameter.
Flow characteristic values →  59