Manual
Construction details
Pre-calibration
This model is equipped with a
pressure setting indicator for
the commissioning operation.
The system charge pressure
can be input by
means of the
adjusting screw,
before the start
of the system
charging phase.
Anti-stick materials
The central housing containing
the moving parts and the internal
compensating spindle are made
of a low adhesion coefficient
plastic. This material minimises
the risk of for
mation of scale
deposits, the main cause of
malfunctions.
Diaphragm-seat seal
The useful working surface of the diaphragm is particularly
large, in order to guarantee greater precision and sensitivity
when working with minimum pressure differences.
This feature is also
useful in that it
gives greater power
to the sliding of
the spindle and
overcomes friction.
In view of the low flow rates involved, the filling unit seat has been
designed with the smallest possible diameter.
This factor, combined with
the extended surface of
the diaphragm, creates an
optimum dimensional ratio
for a piece of equipment
which must maintain its
operating characteristics
unchanged over time.
Spindle guide
In order to reduce the frictional
surfaces, the spindle unit guide has
been positioned in the upper part of
the device.
It consists of four
spokes formed
directly on the
plastic central
support.
Removable filter cartridge
The cartridge containing the operating mechanisms, protected by
a large surface area strainer, is removable. This makes it very easy
and quick to carry out inspections, internal cleaning and even
replacement of the cartridge itself.
0
1
2
3
4
0
10
20
30
40
50
CALEFFI
bar
psi
➩
Dimensions
DC
B
A
1/2"
B
4
13/16
“
C
1
15/16
“
D
4”
A
A
Code
553542A
A
1/2”
3/4”
1/2”
SWT
1/2”
SWT
B
1/2”
1/2”
1/2”
1/2”
C
4
3/4
“
4
5/8
“
4
5/8
“
4
11/16
“
D
1
3/8
“
1
3/8
“
1
3/8
“
1
3/8
“
Code
573403A
573503A
573409A
573493A
A
1/2"
1/2”
SWT
B
1/2”
1/2”
C
9
3/16
“
9
1/8
“
D
1
3/8
“
1
3/8
“
Code
573002A
573009A
A
A’
B
C
D E
E
4”
4”
A’
1/2”
3/4”
1/2”
SWT
1/2”
NPT
A’
1/2"
1/2”
NPT
BACKFL
O
W
PREV
E
Series:
5
73
Sizes:
1/2”
-3
/4”
S/
N
VENT
A
A’
B
C
D
BACKFL
O
W
PREVE
Series:
5
73
Sizes:
1/2”
-3
/4”
S/
N
VENT