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11
Madas Technical Manual
- 7|7.3 - REV. 0 of 1
st
Apr 2019
MVB/1 MIN
• If, after installing the gaskets, there is still an excessive space in between, do not try to reduce the said gap by excessively
tightening the bolts of the device;
• The arrow, shown on the body (
6
) of the device, needs to be pointing towards the application;
• Insert the relative washers inside the bolts in order to prevent damage to the flanges during tightening;
• When tightening, be careful not to “pinch” or damage the gasket;
• Tighten the nuts or bolts gradually, in a “cross” pattern (see the example below);
• Tighten them, first by 30%, then by 60% and finally 100% of the maximum torque (see the table below according to EN
13611);
Diameter
DN 25 DN 32 DN 40 DN 50 DN 65 DN 80 DN 100 DN 125 DN 150
Max torque (N.m)
30
50
50
50
50
50
80
160
160
• Tighten each nut and bolt again clockwise at least once, until the maximum torque has been achieved uniformly;
Common procedures (threaded and flanged devices):
• Install the shut off valve upstream of the adjustment devices.
• The device can also be installed vertically without affecting correct operation. It cannot be put in upside
down (with the reset knob (
1
) pointing downwards);
• IMPORTANT
: Using specific pipe and connections, connect the fitting (
16
) of the shut off valve and any
point in the piping downstream from the regulator (normally at a distance of 5 DN).
• During installation, avoid debris or metal residues from getting into the device;
• To guarantee mechanical tension-free assembly, we recommend using compensating joints, which also adjust to the pipe’s
thermal expansion;
• If the device is to be installed in a gas train, it is the installer’s responsibility to provide suitable or correctly sized supports
to hold and secure the assembly. Never, for any reason whatsoever, leave the weight of the ramp only on the connections
(threaded or flanged) of the individual devices;
• In any case, following installation, check the tightness of the plant;
3.3 - INSTALLATION IN PLACES WHERE THERE IS THE RISK OF EXPLOSION (DIRECTIVE 2014/34/EU)
The valve complies with Directive 2014/34/EU as group II equipment, category 2G and as group II equipment, category 2D;
consequently, it is suited for installation in zones 1 and 21 (besides zones 2 and 22) as classified in Annex I of Directive
99/92/EC.
The valve is not suitable for use in zones 0 and 20, as defined in aforementioned Directive 99/92/EC.
To determine the qualification and size of the danger zones, please refer to standard IEC EN 60079-10-1.
If installed and subject to maintenance in full compliance with all conditions and technical instructions provided in this manual,
the device does not pose a source of specific hazards: in particular, under conditions of normal operation, the valve is
expected to emit a flammable substance into the atmosphere only occasionally.
The valve can be dangerous with respect to the presence of other devices nearby only if case of working diaphragm (
15
)
and safety diaphragm (
12
) failure. In this case, the valve becomes a source of explosive atmosphere emission of continuous
degree and, as such, it can generate hazardous areas 0 as defined in Directive 99/92/EC.
In particularly critical installation conditions (unattended areas, poor maintenance or poor ventilation) and especially if there
are potential sources of ignition and/or hazardous equipment near the valve in regular operation, as they may generate electric
arcs or sparks, a preliminary assessment of the compatibility between the valve and such equipment must be carried out.
In any case, every useful precaution must be adopted so as to prevent the valve from generating zones 0: for example,
annually verify regular operation, possibility of changing the degree of emission of the source or intervening on the external
explosive substance discharge.
For this purpose, the threaded hole (G 1/4) (
14
) can be connected to the outside (using appropriate fittings and pipe) by
removing the dust cap (
13
).
