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Technical Manual MT 188-E
2.0 INSTALLATION
2.1
GENERAL
Before installing the valve, it is necessary to make sure that:
a)
the valve can be inserted in the forecast space and is sufficiently
accessible for performing the following maintenance operations;
b)
the upstream and downstream piping are on the same level and
are able to support the valve weight;
c)
the inlet/outlet flanges of the piping are parallel;
d)
the inlet/outlet flanges of the valve are clean and the valve itself
has not been subject to damage during transport;
e)
the piping is clean, removing any residual impurities such as
welding scraps, sand, paint residues, etc. - also check that they
do not show sign of damages, corrosion, etc.
Provisions that are usually required to be observed are shown in Fig. 5.
Fig. 5
After having performed the above mentioned checks, it is possible to install the valve
on the line paying attention to position its body in such a way that the gas flows in the
same direction of the arrow stamped on the body itself.
To obtain the correct operation it is essential that the downstream impulse circuit is
connected to a straight section of the downstream piping having a length complying
to Fig. 5 (therefore, without any signal turbulence), as well as that the maximum gas
speed at the connection point does not exceed 30 m/sec.
In order to avoid deposits of impurities and condensate in the pressure feeding
connection piping, provide for the following:
a)
The piping shall always be positioned on a descending slope towards the
connection of the downstream piping with a slope of about 5 - 10%;
b)
Piping connections shall always be positioned on the upper part of the piping
and the hole on the piping shall not show any burrs or projections towards the
internal side.
The most frequent types of installation on a gas pressure reduction line of the valve
SBC 187 are shown in Fig. 6 and Fig. 7.
Fig. 6 shows the installation of the valve on a generic piping segment.
Fig. 7 shows the installation of the valve on a gas pressure reduction
line as safety in case of fault of the pressure regulator.
1 Slam-Shut Valve
2 Pressure regulator
3 Pilot
4 Upstream gauge
5 Downstream gauge
6 Drain valve to the atmosphere
V1 Upstream on/off valve
V2 Downstream on/off valve
NB.
IT IS RECOMMENDED NOT TO INTERPOSE
ON/OFF VALVES ON THE IMPULSE CONNECTION
POINTS
6
Fig. 6
Fig. 7
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