GEM 673 Installation, Operating And Maintenance Instructions page 30

Important:
If the diaphragm is not screwed into
the adapter far enough, the closing
force is transmitted directly onto
the threaded 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
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.
Compressor and bonnet fl ange seen from
below:
The compressor is fi xed to the spindle for all
diaphragm sizes.
673_us
mounted diaphragm
12.3.2 Mounting a
concave diaphragm
Recess of compressor
Diaphragm boss
1. Move bonnet A to the closed position.
2. Screw new diaphragm tightly into the
compressor manually.
3. Check if the diaphragm boss fi ts closely
in the recess of the compressor.
4. If it is diffi cult to screw it in, check the
thread, replace damaged parts (only use
genuine parts from GEMÜ).
5. When clear resistance is felt turn back
the diaphragm anticlockwise until its bolt
holes are in correct alignment with the
bolt holes of the bonnet.
12.3.3 Mounting a
convex diaphragm
1. Move bonnet A to the closed position.
2. Invert the new diaphragm face manually;
use a clean, padded mat with bigger
nominal sizes.
Diaphragm face
3. Position the new backing diaphragm
onto the compressor.
4. Position the diaphragm face onto the
backing diaphragm.
5. Screw diaphragm face tightly into the
compressor manually. The diaphragm
boss must fi t closely in the recess of the
30 / 40
Threaded pin
Threaded pin