Flowserve NRG 16-50 - Manual (Page 17)

7
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The seating surfaces of the standpipe or the flange provided on the vessel must be
accurately machined, see Fig. 12 .
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If the level electrode NRG -50 is to be installed in a flanged standpipe DN 50 use
only the GESTRA PN 60 hat flange . Fig. 11
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Do not bend electrode tip when mounting.
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Use only the joint rings supplied with the electrode.
NRG 6-50, NRG 7-50, NRG 9-50: 7 x 3, form D, DIN 7603, .430
NRG -50: 33 x 39, form D, DIN 7603, .430
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Do not lag electrode body above the hexgonal section!
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Do not insulate electrode thread with hemp or PTFE tape!
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Do not apply conductive paste or grease to the electrode thread!
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Make sure that the air distance between the electrode rod and earth (flange, vessel
wall) is not less than 4 mm. Fig. 11, Fig. 16-22
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Observe the minimum distances for the installation of the electrode!
Attention
Note
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One level electrode NRG ...-50 can be installed together with one GESTRA level
electrode, one level switch or transmitter for water level control and high level alarm
in one single protection tube or level pot (inside diameter 00 mm). Fig. 18. If the
electrode NRG ...-50 is installed inside the vessel, it must be at least 40 mm away
from the upper vent hole.
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The installation of two water-level limiting electrodes NRG ...-50 in one single
standpipe is not allowed.
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For the approval of the boiler standpipe the relevant regulations must be considered.
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Refer to pages 8 – 9 for typical installation examples.
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The angle of inclination of the electrode must not exceed 45°, with the length of the
electrode rod being limited to 000 mm. Fig. 17, 21
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For outdoor installations please use level electrode NRG ...-50 F. Level electrodes with
this suffix (F) feature a terminal box made from aluminium.
Tools
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Open-end spanner A. F. 3, DIN 30, ISO 338
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Open-end spanner A. F. 9, DIN 30, ISO 338
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Open-end spanner A. F. 4, DIN 30, ISO 338
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Scriber
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Hacksaw
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Flat file, medium cut, DIN 76, form A
Installation
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