3.3 Lubrication
3.3.1 General
Choose the lubricant according to the operating
conditions . This lubricant should be neutral and
non detergent . Important:
• A lack of lubricant could cause premature wear
of the meter .
• An excess of lubricant can also induce prob-
lems . A surplus of lubricant can contaminate the
measuring chamber, may degrade the metrol-
ogy and cause damage to the bearings and the
impellers due to the mixture of lubricant and
small impurities contained in the gas .
• Always drain the end-covers before moving the
meter .
3.3.2 Choice of lubricant
Viscosity: The viscosity has been calculated to en-
sure mechanical and metrological performance
of the meter .
Commercial references: Annex 3 contains a list
of commercial lubricants usable for industrial gas
except gases such oxygen and halogens . For oth-
er gases, please consult us .
3.3.3 Capacity of end covers: See Annex 4
3.3.4 Filling and draining procedure
See Annex 5 for the location of fill, drain plug and
sights .
Filling and draining operations should be carried
out with the meter installed in the piping, but not
pressurised, though the use of Pete's Plugs may
allow lubricant levels to be "topped up" while the
meter is pressurised (up to 20 bar) . See Annex 9 .
Both front and rear covers must be filled with lu-
bricant, except for the Delta Compact aluminium
and Delta S1-Flow steel for which only the front
cover must be filled .
Adjusting the level of oil:
General case: The level is correct when it passes
the centre
of the lowest sight .
Steel-bodied meters: The lubricant must be filled
until it flows out of the level point "L"
• DN50 S1-Flow: Only the front cover must be
filled with oil . 4 plugs "F" or "D" are available to
Fill or Drain the cover; the lowest one must be
used for draining . Depending of the orientation
of the meter, one level point "L1" or "L2" must
be used to adjust the level of oil i . e . unscrewed
before the filling . The lubricant has to be filled
in "F" until it flows out of the level point "L", only
the lowest level point must be used to adjust
the level of oil .
DN80: The lubricant must be filled in "F" until it
flows out of the level point "L" .
• In some installations, stations or cabinets espe-
cially, the rear lubricant sight is not always easily
readable . In this case, proceed as follows:
• Depressurise the meter .
• Drain the end cover .
• Using a graduated container, fill the end cover
with the volume defined in Annex
4 Accessories
4.1 Electrical accessories
Remarks about using the meter in potentially haz-
ardous areas (ATEX):
• Pulse transmitters must be connected to intrin-
sic safe circuits, according to EN 60079-11 .
• Clean the meter head only with a cloth damped
with water .
• All exposed aluminium parts must be suitably
protected (using paint, varnish, etc) if a film of
rust is possible from dust in the environment .
• The meter must be taken in account in the light-
ning risk evaluation of the complete installation .
• Tools used for installing, removing or repairing
the meter on site must be appropriate for use
in the hazardous area bearing in mind that the
hazardous area classification during meter re-
placement may differ from that during normal
meter operations .
• The meter shall not be exposed to flame, ioni-
sing radiation, ultrasound or strong electroma-
gnetic field .
4.1.1 Low frequency transmitter (furnished as
standard)
The meter is normally delivered with a double
LF pulse output transmitter . The LF is a dry reed
switch and is normally open . See the name plate
of the meter and Annex 6 for connection infor-
mation .
4.1.2 Anti tampering
The meter is delivered as standard with an anti
tampering switch . It is a dry reed switch and is
normally closed . See the name plate of the meter
for connection details .
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