Media Not Reaching the Pump

Got a call from an Engineer " hey , how come the oil cannot enter the pump suction "
Any chokage . valve open ? Answer "No ''
Suction is positive

For this case ,the suction head is very low due to close loop installation and discharge line is also
pressurised ,high back pressure
When the pump was removed and new pump installed ,the pump should be primmed
or air release by remove the nut on the pump body ,then plug back the nut and start pump
make sure rotation is correct

If it is negative suction. the suction line must be filled with media for the first time operation
and make sure foot valve is installed if it is not a self primming pump
Some Engineers still think that self primming pump need not be primmed at all

In most cases .it is the failure to read operation manual provided before commissioning
Pump suppliers will always be called to go to site before the Engineer would determine the
fault .always the pump fault , not working