VEGA VEGABAR 44 Profibus PA - Manual (Page 34)

34 VEGABAR 44 (Profibus PA)
Instrument modification
6.3 Exchange of the hygienic form
seal
The ceramic measuring cell is sealed by a
gapless, radial form seal on VEGABAR 44
process pressure transmitter with hygienic
fitting. This form seal can be exchanged by
the user without readjustment being neces-
sary. The criteria and time periods for such
an exchange are defined by process condi-
tions and hygienic requirements.
Important:
Only use the original VEGA replacement part
as seal ring!
Note the following procedure when exchang-
ing the seal.
Removal procedure:
1 Pressure transmitter should be unpres-
surized (switch off process pressure or
empty vessel).
2 Loosen the hexagon head screw (46 mm
across flats) (1) by turning counter-
clockwise
Note!
The process connection (2) (i.e. compression
nut) must not be loosened!
3 Completely loosen pressure screw and
remove the pressure transmitter from the
process connection
Note:
Should the pressure transmitter turn by loos-
ening the pressure screw, it can be held by
the adapter (3) with a wrench (SW 46).
4 Slightly lift the form seal (5) (with a knife
or something similar) and loosen it from
the ceramic measuring cell
5 If the form seal (5) does not cover the
measuring cell, it should be carefully
removed from the process connection.
Installation procedure:
6 Pull a new form seal (5) over the measur-
ing cell (the conical end should point
towards the process connection!).
7 Insert the pressure transmitter carefully
into the process connection by turning
clockwise.
8 Tighten hexagon head screw (46 mm) (1)
to its fixed position (45 Nm).
9 Return the housing (4) of the pressure
transmitter to its original position
Exchange of the form seal is now finished.
Ensure appropriate disposal of the removed
seal.
1 Hexagon pressure screw
2 Process connection
3 Adapter
4 Housing
5 Form seal