RDL
6.1.3 Priming the pump and checks to be carried out
Before start-up, the pump, the suction line and (if applicable) the thermosiphon tank must be vented and primed. The shut-off
element in the suction line must be fully open.
Fully open all auxiliary lines provided (flushing, sealing, cooling liquid etc.) and check the through flow.
For water cooling, use suitable non-aggressive cooling water not liable to form deposits and not containing suspended solids.
(Hardness: on average 5dH (ca. 1 mmol/l); pH > 8, or conditioned and neutral with regard to mechanical corrosion).
Inlet temperature tE = 10 to 30 ºC
Outlet temperature tA = max. 45 ºC
Dry-running will result in failure of the mechanical seal and must be avoided!
6.1.4 Checking the direction of rotation
When the unit has been connected to the electric power supply, verify the following (local and national regulations have to
be taken into account separately):
For trouble-free operation of the pump, the correct direction of rotation of the impeller is of paramount
importance. If running in the wrong direction of rotation, the pump cannot reach its duty point; vibrations and
overheating will be the consequence. The unit or the shaft seal might be damaged.
Correct direction of rotation:
The direction of rotation must correspond to the direction indicated by the arrow on the pump. This can be verified by switching
the pump on and then off again immediately.
Before checking the direction of rotation make sure that there is no foreign matter in the pump casing.
Never hold your hands or any other objects into the pump.
Do not run the pump without iquid while checking the direction of rotation. If there is no medium
handled available, the motor’s direction of rotation must be checked with the pump de-coupled.
If the pump runs in the wrong direction of rotation, interchange two of the three phases in the control cabinet or motor terminal
box.
6.1.5 Cleaning the plant piping
The cleaning operation mode and duration for
flushing pickling service must be matched to the casing and seal materials used.
6.1.6 Start-up strainer
If a start-up strainer has been fitted to protect the pumps against dirt and/or to retain contamination from the plant, the strainer’s
contamination level must be monitored by measuring the differential pressure so as to ensure adequate inlet pressure for the
pump.
For installation and monitoring, see additional instruction sheet.
6.1.7 Start-up
Before starting the pump ensure that the shut-off element in the suction line is fully open! The pump may be started up against
a closed discharge-side swing check valve or shut-off element. Only after the pump has reached full rotational speed shall the
shut-off element be opened slowly and adjusted to comply with the duty point. When starting up against an open discharge side
shut-off element, take the resulting increase in input power into account.
Pump operation with the shut-off valves in the discharge and suction pipes closer is not permitted.
The permissible pressure and temperature limits might be exceeded. In extreme cases, the pump may burst.
After the operating temperature has been reached and/or in the event of leakage, switch off the unit, allow to
cool down, then re-tighten the bolts between upper and lower volute casing.
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