VEGA D94 Profibus PA - Manual (Page 33)

Pressure transmitter D94 (Profibus PA) 33
Notes
6.2 Exchange of hygienic form seal
on D94
On the hygienic connections AA, CA, LA, LB,
RA, RB, TA of pressure transmitter D94, the
ceramic measuring cell is radially, gaplessly
sealed with a form seal. This form seal (mate-
rial EPDM-FDA) can be exchanged by the
user without the need of a fresh adjustment.
The criteria and the time intervals for such an
exchange of the seal are generally defined
by the process and hygienic requirements.
Important:
Use only original replacement seals from
VEGA!
Please note the following exchange proce-
dure.
Removal procedure:
• Pressure transmitter should be unpres-
surized (switch off process pressure or
empty vessel).
• Loosen the hexagon pressure screw (4)
(width across flats, 46 mm) by turning to
the left.
Note!
The process connection (6) (e.g. compres-
sion nut) must not be loosened!
• Turn the adapter (3) below the pressure
transmitter housing with a screwdriver
(with across flats, 36 mm) briefly to the
left (to loosen the seal).
• Pull the complete pressure transmitter on
the housing (1) out of the process con-
nection by carefully turning to the left.
• Slightly lift the form seal (5) and loosen
from the ceramic measuring cell.
• If the form seal (5) does not completely
encircle the measuring cell, it must be
carefully removed from the process con-
nection.
Installation procedure:
• Put the new form seal (5) over the meas-
uring cell (the conical end must point to
the process connection!).
• Carefully insert pressure transmitter into
the process connection by turning clock-
wise.
• Tighten hexagon pressure screw (4)
(width across flats, 46 mm) (45 Nm).
• Turn the housing (1) of the pressure
transmitter into the original position.
The exchange of the form seal is now fin-
ished; the removed seal must be properly
disposed of.
1 Pressure transmitter
2 Headless screw (avoids overwinding and must not be
removed)
3 Adapter
4 Hexagon screw
5 Form seal
6 Process connection
1
2
3
4
5
6