PIETRO FIORENTINI REFLUX 819/FO, Техническое руководство

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TECHNICAL MANUAL MT103
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The list of symbols used and their meanings are listed below:
= According to Directive PED
Pemax = maximum inlet operating pressure of the apparatus
bpe = range of variability of the inlet pressure of the pressure regulator in normal operating conditions
PS = maximum pressure which can be supported by the structure of the body of the apparatus in safety conditions
Wa = range of setting of the pressure regulator/pilot/pre-regulator which can be obtained using the parts and the
setting spring fitted at the moment of testing (without changing any components of the apparatus, that is). In
piloted regulators, the pilot is considered as a separate apparatus with its own setting range Wa
Wh = range of setting of the pressure regulator/pilot/pre-regulator which can be obtained using the setting springs
indicated in the associated tables and also by changing some other part of the apparatus (reinforced gasket,
diaphragms etc.). In piloted regulators, the pilot is considered as a separate apparatus with its own setting range
Wh
QmaxPemin = maximum flow rate with minimum pressure at the pressure regulator inlet
QmaxPemax = maximum flow rate with maximum pressure at the pressure regulator inlet
Cg = experimental coefficient of critical flow
AC = regulation class
SG = closing pressure class
AG = intervention accuracy
Wao = range of intervention for the over pressure of slam-shut, relief and safety valves and accelerators which can
be obtained using the setting spring fitted at the moment of testing. In the piloted safety valves, the pilot is
considered as a separate apparatus with its own setting range Wao
Who = range of intervention for the over pressure of slam-shut, relief and safety valves and accelerators which can
be obtained using the setting springs indicated in the tables. In piloted safety valves, the pilot is considered as a
separate apparatus with its own setting range Who
Wau = range of intervention for pressure decrease of slam-shut pressure which can be obtained using the setting
spring fitted at the moment of testing
Whu = range of intervention for pressure decrease of slam-shut pressure which an be obtained using the setting
springs indicated in the tables.
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 8 and 9 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.
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