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7.6 Diaphragm breakage
If the diaphragm leaks or is broken, dosing liquid
escapes from the drain opening (fig.
, pos. 11) on
the dosing head.
In case of diaphragm breakage, the safety
diaphragm (fig.
, pos. 1) protects the pump
housing against ingress of dosing liquid.
When dosing crystallising liquids the drain opening
can be blocked by crystallisation. If the pump is not
taken out of operation immediately, a pressure can
build up between the diaphragm (fig.
, pos. 4) and
the safety diaphragm in the flange (fig.
, pos. 2).
The pressure can press dosing liquid through the
safety diaphragm into the pump housing.
Most dosing liquids don’t cause any danger when
entering the pump housing. However a view liquids
can cause a chemical reaction with inner parts of the
pump. In the worst case, this reaction can produce
explosive gases in the pump housing.
To avoid any danger resulting from diaphragm
breakage, observe the following:
•
Perform regular maintenance. See section
•
Never operate the pump with blocked or soiled
drain opening.
– If the drain opening is blocked or soiled,
proceed as described in section
7.6.1 Dismantling in case of diaphragm
breakage
.
•
Never attach a hose to the drain opening. If a
hose is attached to the drain opening, it is
impossible to recognise escaping dosing liquid.
•
Take suitable precautions to prevent harm to
health and damage to property from escaping
dosing liquid.
•
Never operate the pump with damaged or loose
dosing head screws.
7.6.1 Dismantling in case of diaphragm breakage
This section refers to fig.
.
1. Make system pressureless.
2. Empty dosing head before maintenance and
flush it if necessary.
3. Take suitable steps to ensure that the returning
liquid is safely collected.
4. Dismantle suction, pressure and deaeration
hose.
5. Remove the cover (9).
6. Loosen screws (8) on the dosing head (7) and
remove with discs.
7. Remove the dosing head (7).
8. Unscrew diaphragm (4) counter-clockwise and
remove with flange (2).
9. Make sure the drain opening (11) is not blocked
or soiled. Clean if necessary.
10. Check the safety diaphragm (1) for wear and
damage. Replace if necessary.
If nothing indicates that dosing liquid has entered the
pump housing, go on as described in section
7.4.3 Reassembling the diaphragm and valves
Otherwise proceed as described in section
7.6.2 Dosing liquid in the pump housing
.
7.6.2 Dosing liquid in the pump housing
If dosing liquid has entered the pump housing:
•
Send the pump to Grundfos for repair, following
the instructions given in section
•
If a repair isn’t economically reasonable,
dispose of the pump observing the information
in section
Warning
Danger of explosion, if dosing liquid has
entered the pump housing!
Operation with damaged diaphragm can
lead to dosing liquid entering the pump
housing.
In case of diaphragm breakage,
immediately separate the pump from the
power supply!
Make sure the pump cannot be put back
into operation by accident!
Dismantle the dosing head without
connecting the pump to the power supply
and make sure no dosing liquid has
entered the pump housing. Proceed as
described in section
Warning
Danger of explosion, if dosing liquid has
entered the pump housing!
Do not connect the pump to the power
supply!
Warning
Danger of explosion!
Immediately separate the pump from the
power supply!
Make sure the pump cannot be put back
into operation by accident!
