PIETRO FIORENTINI NORVAL, Installation, Commisioning And Maintenance Instructions

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TECHNICAL MANUAL MT044
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5.2 GAS INPUT, CONTROL OF EXTERNAL TIGHTNESS AND SETTING
The apparatus pressurization operation must be carried out very slowly. To protect the apparatus from damage,
the following operations
must never be carried out:
- Pressurization through a valve located downstream from the apparatus itself.
- Depressurization through a valve located upstream from the apparatus itself.
External tightness is guaranteed if no bubbles form when a foam medium is applied on the element under pressure.
The regulator and any other apparatuses (slam-shut, monitor) are normally supplied already set for the
desired set-point. It is possible for various reasons (e.g., vibration during transport) for the settings to be changed
while remaining within the values permitted by the springs used.
We therefore recommend checking the settings using the procedures illustrated below.
Tables 7 and 8 give the recommended set-points for the apparatuses in the various installation arrangements. The
figures in these tables can be useful both when checking existing set-points and for modifying them should this
become necessary later.
In installations consisting of two lines, we suggest commissioning one line at a time, starting from the one with
the lower set-point, known as the “reserve” line.
The set-points of the apparatuses in this line will obviously
deviate from those specified in the tables 7 and 8.
Before commissioning the regulator you must check that all the on/off valves (inlet, outlet, any by-pass) are
closed and that the gas is at a temperature which will not lead to malfunction.
5.3 COMMISSIONING THE REGULATOR
If there is also a relief valve in the line, refer to par. 3.1 to check it.
1) very slowly open the inlet on/off valve V1;
2) check on the pressure gauge 5 that the pressure does not exceed the pre-established set-point, plus a tolerance
of 10% due to the closing force of the regulator;
3) stabilise the upstream and downstream pressures and open the bleed cock 6;
4) check on the pressure gauge 5 that the downstream pressure is at the set-point. If it is not, adjust the setting
by means of the provided screw 74 (fig. 1), turning it clockwise to increase it and anticlockwise to decrease it;
5) close the bleed cock and check the pressure set-point;
6) check the tightness of all the joints between the on/off valves V1 and V2 using a foam solution;
7) very slowly open the downstream on/off valve V2, until the line is completely filled.
Fig. 12