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Dosaodor-D
and that the complete system (pipes, pipe connections and
equipment) is pressure tight and free from leaks.
In case of effective National regulations, above
recommendation shall be mandatory.
Proceed as follows for these checks: (use the diagram from
figure 4 as a reference)
•
Close the odorant input valve installed at the base of the
pickup tank.
•
Open the three gas on/off valves installed on the main
gas line (Upstream station, downstream regulators /
upstream measurement, upstream solenoid valve key 23)
•
Using a suitable spray, check for any gas leaks (check
ALL fittings)
•
Proceed by switching on the electronic control unit, as
indicated in paragraph "Control Unit Power-on" on page
28. With this procedure, solenoid valves 8 and 10 will
open automatically and will remain open for no longer
than 2 minutes. After this interval, the valves will close,
activating the control unit alarm with a signal indicating
odorant recharge failure
•
Check the section of line connecting the pneumatic panel
with the odorant tank, including odorant filter for any gas
leaks. If no leaks are detected, proceed with priming the
entire system.
Pneumatic Panel Startup
(see figure 2, 3 and 4)
Preparation procedures for the pneumatic panel (key 27) are
simple and do not involve any special operations. See the
following procedures:
•
Open the four on/off gas valves installed on the main gas
line (Upstream filters, Downstream regulators, Odorant
injection, High-pressure gas supply to the panel)
•
Open the two on/off odorant valves installed on the
pneumatic panel
•
Open the on/off odorant valve (key 7) installed at the
base of the odorant storage tank
•
Switch on the electronic control unit (key 28)
•
Set the key to "Prog. -ON"
•
Press the WASHING push-button located in the
"SYSTEM" section of the control unit
•
Check the programmed data for accuracy
•
Eliminate any alarms present by pressing the Red
ALARM RESET - button
•
Press the "PUSH" button until the section of the line joining
the pneumatic panel and the injection point are completely
drained. Keep the button pressed approx. 12 seconds for
each meter of pipeline installed (DN 6 x 4 mm).
Once the priming / drainage phase is completed, the system
is ready for operation. Check Loc. 11 and verify the flow
computer is transmitting the gas volumes correctly. The
Dosaodor control unit counter should increase correctly
corresponding to the volume computer counter.
34
Check the programmed data, carefully focusing on the
values entered for Locations from Loc:00 to Loc:05.
Switch off the Dosaodor-D control unit. Verify the key is on
the "PROGRAMMING-ON" setting. Press ENT and keep it
pressed to switch on the control unit. (This procedure sets all
the internal counters to zero).
Press the AUTOMATIC button located in the SYSTEM section
and set the key to Prog.-OFF. The system will start dosing the
odorant proportionally to the flow rate of the gas in transit.
Operation (see figures 2, 3 and 4)
See diagram in figure 4 for Dosaodor-D operation, the
diagram from figure 4 is taken as a reference. The diagram
shows the entire odorization "chain", recharging by means
of transportable tanks, the absorption-type emergency tank
and the injection system.
This section only refers to the injection system and not the
absorption type emergency tank devices.
Preliminary verifications:
•
By means of the slaved pneumatic valve (key 24),
which is controlled by the solenoid valve (key 23)
located on the downstream section of the absorption-
type tank odorizer, the Dosaodor-D control unit can
activate or deactivate the operation of the traditional
absorption-type emergency tank circuit in the event of
malfunctioning or power drop.
•
The liquid to be injected is collected through the bottom
absorption-type odorizer valve. If the latter is not
present, collection takes place through the lower part of
the tank level indicator.
•
Pressure intakes to drive the injection liquid are created
through the utilization of intakes that are always present
on the REMI (reducing and metering) stations, taking
measures to double them by inserting a tee-pipe
coupling and a second needle valve to maintain the
existing intakes functional.
The pressure collected upstream from the primary reduction
unit is sent to a pressure regulator, Mod. SA/2 (key 6). This
regulator reduces the inlet pressure level from a maximum of
75 bar (1087.8 psi) to a set value equal to the station output
pressure increased by 3 bar (43.5 psi).
This pressure is sent to a second regulator, Mod. SA/2
(key 5), where it is reduced to a level equal to the station
downstream pressure increased by 0.6 bar (8,7 psi).
Therefore, whatever downstream pressure level exists, the
pressure output from this regulator will be greater by 0.6 bar
(8,7 psi), ensuring a steady pressure differential, which
permits proper injection of the odorant.
In addition to the double pressure regulator, the regulation
circuit also has a relief valve (key 11), set and capable of
guaranteeing safe conditions should both regulators undergo
malfunctioning at the same time. This pressure is intercepted
by the three-way solenoid valve (key 4) which under non-
working conditions, provides for pressurizing the volume
sampler (key 8) in which a certain odorant volume is found.
A control pressure-gauge (key 10) is located on the sampler.
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