Madas RG/2MCS Manual Del Usuario página 20

6.4 - Adjusting the relief valve (differential DfRv)
NOTE: The relief valve (if any) in these regulators is differential, therefore the range value (DfRv) indicated must be added to
the range value of the outlet pressure (Pa).
Example: Pa=32-60 mbar - DfRv=15-40 mbar.
Means that the relief valve can be calibrated from: (Pa min + DfRv min) = 32+15=47 mbar to: (Pa max + DfRv max) =
60+40=100 mbar
Therefore the effective range of the relief valve (in this case) is 47-100 mbar.
• Start the system and set the shut off as described in point 4.0;
• Slowly close the valve downstream of the regulator;
• Loosen and remove the cap (1);
• Use the appropriate socket spanner (see fig. 1, 2 and 3) tighten the nut to stroke end (19);
• Use the 10 mm socket spanner to press the adjustment nut (19) and increase the pressure Pa, reading it on the pressure
gauge, up to the desired setting value;
• Without pressing further, slowly loosen the adjustment nut (19) until the pressure Pa begins to decrease, shown on the
pressure gauge;
• In this case, the relief valve is set to the desired value;
• Remove the socket spanner and close the cap (1).
7.0 - RECOMMENDED PERIODIC CHECKS
• Use a suitable calibrated tool to ensure that the bolts are tightened as indicated in 3.2;
• Check the tightness of the flanged/threaded connections on the system;
• Check the tightness and operation of the regulator/shut off/relief valve;
The final user or installer is responsible for defining the frequency of these checks based on the severity of the service conditions.
7.1 - CHECK THAT THE MAXIMUM PRESSURE SHUT OFF VALVE IS WORKING (OPSO)
Reset the shut off device and close the valve downstream of the regulator;
Method 1:
1. Loosen and remove caps (1) and (23);
2. Use the same tool (shown in fig. 3) to press the nut (19) and slowly increase the downstream pressure until the
device is triggered;
3. Tighten the caps back to their original position and repeat the Pa setting steps (6.4);
Method 2:
1. Alternatively, use an auxiliary gas pressure to slowly increase the downstream pressure until the device is triggered
(so as to avoid having to set the Pa again).
7.2 - CHECK THAT THE MINIMUM PRESSURE SHUT OFF VALVE IS WORKING (UPSO)
• Reset the shut off device and close the ball valve upstream of the regulator;
• Open the relief valve, downstream of the device, partially and slowly. As the outlet pressure decreases slowly it will cause
the minimum shut off to trigger at its setting value;
• Repeat the trigger step 2-3 times to make sure that the system functions correctly. Between one trigger and another, set the
downstream pressure back to the setting value.
RG/2MCS - RG/2MBZ
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Madas Technical Manual - 5|5.2b - REV. 0 of 2 Sep 2019
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