9
MT 235 – EN ed.2015 (Rev.A)
2.2
CONNECTING THE EQUIPMENT
The regulators series Dival 500 can be equipped with:
internal sensing line.
in external sensing line
external sensing line (monitor version)
Where forecast, the connections between the equipment and the piping have to be carried out using a stainless steel or
copper pipe, having a minimum internal diameter of 8 mm.
Figure 7: Installation diagram
The installation on a system with a multiple sensing connection point (fig. 8) aims at deriving from
a single point all the pressure sensing signals reaching the various reduction and safety
equipment and the related accessories.
The regulator must be installed in the line with the arrow on the body positioned in the gas flow
direction.
Where forecast, in order to obtain a good regulation it is essential that the position of the outlet
pressure sensing points and the gas speed at the sensing point meet the values given in table
2.3. When it is used in gas pressure reduction stations, the regulator shall be installed at least in
compliance with the requirements of the EN 12186 or EN 12279 standards. All possible relief
points due to any breakages of sensors/ membranes shall be conveyed in compliance with the
EN 12186 or EN 12279 standards.
In order to prevent impurities and condensation from building up in the pressure sensing tubes, it
is advisable to provide for the following:
the tubes shall always be positioned on a descending slope towards the connection
of the outlet piping with a slope of about 5 - 10%;
tube branch connections shall always be welded on the upper part of the piping itself and the hole on the piping shall
not show any burrs or projections towards the internal side.
To avoid breakages or unwanted deformations, it is recommended to provide for the following:
the equipment shall be installed pursuant to the regulations in force and the good practice
there shall not be any external loads acting on the device
the equipment shall be provided with adequate protection and grounding means to protect it against stray currents
and electrostatic potential differentials
the equipment shall be used within the limits set on the rating plate
Table 2.3
In the regulator outlet piping, gas speed shall not exceed the following values:
Vmax = 25 m/s for 1.5 < Pd < 5 bar
Vmax = 20 m/s for 0.5 < Pd < 1.5 bar
Vmax = 15 m/s for Pd ≤ 0.5 bar
Regulator
External
sensing line Pressure gauge
Relief valve
On-off valve
Regulator
External
sensing
line
Pressure
gauge
Relief valve
On-off valve
Figure 8
