PIETRO FIORENTINI APERFLUX 101 Technical Manual Download Page 5

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Technical manual

MT 208-E

1.0 INTRODUCTION

The scope of this manual is to provide the essential information for
the installation, commissioning, disassembly, re-assembly and
maintenance of APERFLUX 101 regulators.
It is also appropriate to provide a brief illustration of the main features
of the regulator and of its accessories.

1.1 MAIN

FEATURES

The

APERFLUX 101

pressure regulator is a regulator for medium and

high pressure.
The

APERFLUX 101

is a “fail open” type regulator and therefore opens

in the event of:
-  rupture of the main diaphragm
-  no feed in the pilot circuit
The main specifications of this regulator are:
-  Design pressure: up to 85 bar (1232,8 Psi)
-  Working temperature range: -20°C + 60 °C (-4 to + 140 °F)
-  Ambient temperature: -20°C + 60 °C (-4 to + 140 °F)
-  Inlet pressure range

bpu

: 1,8 to 85 bar (26,1 to 1232,8 Psi)

- Regulating range possible

: 0,8 ÷ 74 bar (11,6 to 1073,3 Psig)

(depending on the pilot installed)

- Minimum differential pressure 1 bar (14,5 Psig). Recommended >2

bar (29 Psig)

- Precision class

: up to

(depending on the operative conditions)

- Closing pressure class

SG 10

(depending on the operative

conditions)

1.2

OPERATION OF THE PRESSURE REGU-
LATOR WITH SERIES 300 PILOT (fig.1)

In the absence of pressure, the main diaphragm

is maintained in the

closed position by the spring

and rests on the seat of the valve with

grill

. The seal is guaranteed by the contact between the valve

seat 13 and the diaphragm

. In normal working conditions, the

following forces act on the diaphragm

- downwards: the load of the spring

, the thrust deriving from the

control pressure

in the control chamber

and the weight of the

mobile assembly;

- upwards: the thrusts deriving from the upstream pressure

Pu,

the

downstream pressure

and the remaining dynamic components.

The control pressure

is obtained by drawing gas at the pressure

directly upstream from the diaphragm

. The gas is filtered by

the filter incorporated in the

AR100

flow regulating valve. The

pressure

is governed by the pilot which regulates its value. The

regulation is obtained from the comparison of the load of the setting
spring

and the thrust on the diaphragm

deriving from the

downstream pressure. If during operation, for example, there is a
drop in the downstream pressure

below the set point (as a result

of an increase in the flow demand or of a reduction of the upstream
pressure), a state of imbalance of the mobile assembly

is created

and leads to an increase in the opening of the obturator

and

therefore a reduction of the control pressure

. As a result, the

diaphragm

moves upwards increasing the opening of the

regulator until the downstream pressure reaches the set point again.

On the other hand, when the downstream pressure rises beyond the
set point (as a result of a reduction in the demand or with the increase
in the upstream pressure), the obturator

closes and therefore the

pressure

reaches the value of the upstream pressure

. In these

conditions, the diaphragm

goes to the closed position. In normal

working conditions, the obturator

is positioned in such a way that

the pressure

above the diaphragm

is such as to maintain the

downstream pressure around the selected value