Valve Disassembly (Removing Distance Piece From Body); Removing The Diaphragm; Mounting The Diaphragm; General Information - GEM 638 Installation, Operating And Maintenance Instructions

11.1 Valve disassembly
(removing distance piece
from body)
1. Close actuator A by approx. 85 %.
2. Disconnect the valve from the mains
supply.
3. Check whether the actuator weight is
supported securely.
4. Remove the distance piece 3 from the
valve body 1:
Loosen nuts 20 diagonally and remove
them.
DN 25 - 65: Remove bolts 18 along with
washers 19.
DN 80 - 150: Leave stud bolts 18 in the
valve body and remove washers 19.
Important:
After disassembly, clean all parts
of contamination (do not damage
parts). Check parts for potential
damage, replace if necessary (only
use genuine parts from GEMÜ).

11.2 Removing the diaphragm

Important:
Before removing the diaphragm,
please remove the actuator, see
"Valve disassembly (removing
distance piece from body)".
1. Unscrew the diaphragm 2.
2. Clean all parts of the remains of product
and contamination. Do not scratch or
damage parts during cleaning!
3. Check all parts for potential damage.
4. Replace damaged parts (only use
genuine parts from GEMÜ).
638

11.3 Mounting the diaphragm

11.3.1 General information

Important:
Mount the correct diaphragm
that suits the valve (suitable for
medium, medium concentration,
temperature and pressure). The
diaphragm is a wearing part. Check
the technical condition and function
of the valve before commissioning
and during the whole term of use.
Carry out checks regularly and
determine the check intervals in
accordance with the conditions of
use and / or the regulatory codes
and provisions applicable for this
application.
Important:
If the diaphragm is not screwed
into the adapter far enough, the
closing force is transmitted directly
onto the diaphragm pin and not
via the compressor. This will cause
damage and early failure of the
diaphragm and thus leakage of the
valve. If the diaphragm is screwed
in too far no perfect sealing at the
valve seat will be achieved. The
function of the valve is no longer
ensured.
Important:
Incorrectly mounted diaphragm
may cause valve leakage /
emission of medium. In this case
remove the diaphragm, check the
complete valve and diaphragm and
reassemble again proceeding as
described above.
The compressor is fixed to the spindle for all
nominal sizes.
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