Make sure that the pump is always started up with the suction-side shut-off valve fully open and the discharge-side shut-off valve slightly open. However, the pump can also be starded up against a closed swing check valve.
Both gland packings and mechanical seals may exceed the specified temperature limits if run dry. Dry
running may not only result from an inadequately filled seal chamber, but also from excessive gas content in the fluid handled.
Pump operation outside its specified operating range may also result in dry running.
In hazardous areas, gland packings shall only be used if combined with a suitable temperature monitoring device.
In normal pump operation, the highest temperatures are to be expected on the surface of the pump casing, at the shaft
shaft seal and in the bearing areas. The surface temperature at the pump casing corresponds to the temperature of the fluid
If the pump is heated, it must be ensured that the temperature classes stipulated for the plant are observed.
In the bearing bracket area, the unit surfaces must be freely exposed to the atmosphere.
Only a pump unit which is properly serviced and maintained in perfect technical condition will give safe and reliable operation.
This also applies to the reliable function of the rolling element bearings whose actual lifetime largely depends on the operating mode and operating conditions.
Regular checks of the lubricant and the running noises will prevent the risk of excessive temperatures as a result of bearings running hot or defective bearing seals (also see section 7.3).
The correct function of the shaft seal must be checked regularly. Any auxiliary systems installed must be monitored, if necessary, to make sure they function correctly.
Gland packings must be tightened correctly, to prevent excessive temperatures due to packing running hot.