4.1.3 Cyble sensor
A Cyble sensor can be installed onto the totaliser
at any time, see Annex 6 . The Cyble sensor is a
bounce-free transmitter . It allows also the count-
ing of eventual back flows .
4.1.4 Medium & high frequency transmitters
(furnished as option)
The meter can be delivered with medium or high
frequency transmitters . There are inductive sen-
sors, and connection is to a NAMUR- type input
circuit (EN 60947-5-6) .
4.1.5 Pulse values of LF, Cyble sensor, MF
and HF transmitters: see Annex 1
4.2 Gasket-Filter
A "Gasket-filter" can be inserted directly upstream
of flanged meters at the place of the standard
gasket: it is a protection against particles remain-
ing in the upstream pipe . It is recommended to
remove it after approximately 4 to 8 weeks of
operation .
4.3 External dryer cartridge
The meter can be equipped with an external sili-
cagel cartridge for installation in severe environ-
ment conditions . To replace the cartridge, un-
screw the old cartridge, remove the protective
plug of the new cartridge and screw it into the
totaliser .
5 Start-up
5.1 General
The procedure of start-up is always dependent on
the installation configuration .
Before pressurising the meter, the lubrication
procedure should be performed . Pressurisation
or depressurisation should be carried out with
very low pressure change . The pressure change
should not exceed 0 . 3 bar/5 P . S . I . per second .
After start-up, please check the tightness of the
installation .
The proper installation and functioning of the
meter can be verified by a visual control of the
totaliser (to check that the meter runs properly)
and by measuring its pressure loss while running
though the use of Pete's Plugs may allow this
6
pressure loss to be measured while the meter is
pressurised (up to 20 bar) .
5.2 Installation with by-pass:
See Annex 7
START-UP:
Begin with all valves closed .
• Slowly open the by-pass valve to pressurise the
downstream piping .
• When the pressure is balanced downstream,
slowly open the small upstream valve V1 . The
pressure variation should not exceed 0 . 3 bar
per second .
• When the pressure is balanced in the meter,
slowly open the main upstream valve and then
close V1 .
• Slowly open the downstream valve and check
that the meter starts to register the flow .
• Gradually, close the by-pass valve . Check that
the flow rate doesn't exceed the capacity of the
meter .
SHUT DOWN:
• Slowly open the by-pass valve and then close
the upstream and downstream valves on the
meter line .
• Carefully open the small bleeder valve V2 and
depressurise the meter . The pressure variation
should not exceed 0 . 3 bar per second .
• Some gas still inside the meter and the pipe,
therefore sufficient ventilation is required .
5.3 Installation without by-pass: See
Annex 8
START-UP:
Begin with all valves closed .
• Slightly open the upstream valve to pressurise
the meter line . The pressure variation should
not exceed 0 . 3 bar per second . When the pres-
sure is balanced, fully open the upstream valve .
• Slightly open the downstream valve . The valve
should be opened a small amount to maintain:
- The upstream pressure in the meter line .
– A low flow rate in the meter during the
downstream pressurisation (approx . 5%
Qmax) .
When the downstream pressure is balanced, the
downstream valve can be completely opened .
SHUT DOWN:
• Very slowly close the downstream valve and
check that the meter is no longer recording .