Pneumatic level measuring for
Electronic Controllers
Open Bell - system
OPERATING INSTRUCTIONS
DESCRIPTION
CONNECTION OF THE PNEUMATIC TUBE TO
THE OPEN BELL
The Open Bell – system is preferably used in
domestic sewer systems, PSS.
When connecting the pneumatic tube to the
screwing (Bolting) one should act as follows (See
picture):
The measuring procedure is based on the
compression of atmospheric air encircled in system
by the hydrostatic pressure of a liquid column.
The Open Bell as a measuring probe is connected
with an air tube to a pressure switch.
The generated pressure is transformed in the
switch to an analogue signal.
APPLICATION
The implementation of the Open Bell in explosion
hazardous areas (Zone 1) is only possible with
special pressure transformers. These are used by
ITT Flygt in the panel FGC.
1. PG screwing, (4), which is needed to hang in the
Open Bell later, has to be pushed above the
pneumatic tube (1).
2. The pneumatic tube has to be cut right- angled
with a knife (Diagonal side cutting pliers are not
suitable).
3. Afterwards the pneumatic tube has to be
trimmed.
4. Put the pneumatic tube into the connection (3).
Remove:
Push the black ring from the connection to remove
the tube from the connection.
CONNECTION OF T HE PNEUMATIC TUBE TO
THE PANEL
• See installation manual for the corresponding
panel.
WINWORD/TE/40127C.DOC 01/97
Version: 02
Page 1
POSITIONING
• Free hanging at the pneumatic tube
• The pneumatic tube and fasten with clamp at the suspension (Hanging)
• The exact position of the Open Bell depends of the used panel and the construction of the pump shaft.
LAYING OF THE PNUMAT IC TUBE
• Sharp bends and squeezes spots are to be avoided
• In ground and mechanically endangered points the pneumatic tube has to be installed additionally in a
protection pipe. (90° rounding are not allowed in the protection pipe)
• The pneumatic tube has to be lain permanently raising. Loops should be avoided. For this purpose the
pneumatic tube has to be shortened to the necessary length.
• Influences by ultraviolet rays must be avoided.
MAINTENANCE
• The Open Bell and the pneumatic tube have to be controlled regularly with respect to pollution. For this purpose the
pneumatic cable has to be detached from the pressure transformer (panel) and to be blown in the direction of the Open
Bell. After that the Open Bell has to be cleaned at the in- and outside.
TECHNICAL DATA
Temperature range (°C)
Material
Grey cast iron
0-40
Difference in temperature
+ 20 °C within 2 h
Transmission length max. ... m
Measurement range
Connection
Diameter of Bell
Weight
20
0 - 1 m Ws (0 - 0,1 bar)
8 mm Pneumatic tube Type: 8 x 1
100 mm
ca. 2,5 kg
Page 2
Version: 02
WINWORD/TE/40127C.DOC 01/97