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Installation, hydraulic
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fig. 14
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Page 12
4.3
Notes on Installation on Delivery Side
WARNING
EX-pump only:
•
On principle, metering pumps in potentially explosive atmospheres must be equipped
with a safety overflow valve at the outlet side of the pump (serves as protection against
overheating due to overload and against sparks produced by shock due to overload
which has led to the breakage drive parts.)
•
Piston metering pumps, used in temperature class T4, must be equipped with a flow
control at the outlet side (serves as protection against excess temperature due to dry-
running.)
•
For metering pumps with hydraulically actuated diaphragm, the pump must also be
provided with a flow control, if used in temperature class T4. (Protection against
improper heating in case of permanent operation via the internal overflow valve.)
IMPORTANT
Do not exceed permissible nominal pressure! Otherwise the pump may be damaged!
Provide an overpressure facility if the permissible pressure in the pump head can be
exceeded, e.g. by closing a shut-off element or a blockage in the line:
•
Install overflow valve in the delivery line or
•
use an overflow valve integrated in the pump housing (depending on type, refer to
data sheet of the type of pump used).
The following points must be observed with regard to the overflow line when using an
overflow valve:
•
Route the overflow line with a drop into the supply tank under atmospheric pressure
or into an open runoff channel.
•
Connect the overflow line to the intake line, however, only if there is no check valve in
the intake line.
IMPORTANT
Do not use a non-return check valve on the intake side for the overflow return as it may
cause the intake line to tear off.
IMPORTANT
Cut off the return flow from the main line!
Otherwise unwanted mixing in the metering line can occur.
•
Install the metering valve at the injection point.
ProMinent
ProMinent
®
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