Expect the Unexpected inTrouble Shooting

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A customer was using a centrifugal pump, for pump cooking oil used for frying potato chips and
always is used many time

the pump was running for a year without any problem until recently suddenly no flow coming out to the tank . technician start doing as follow

a) test the pump with Water from another tank and flow back to normal
b) shut off test done and pump i s able to achieve required pressure
c)next he checked the NON return valve - no problem
d) and then he suspect the Oil heating tubes got choked but not the case
e) then blame the motor , but electricain confirm motor is good condition

But what he did not do is check suction line.Our technical staff suggest check Y strainer
and true enough ,the Y strainer was fully clogged by small pieces of potato chips

When Y strainer was cleaned ,pump is now runnnig perfectly

Usually when pump is not getting the rated flow . most likely is the suction line problem

a) NPSH A too low for new pumps,which is suction line being too long or pipe diameter
too small , or if  a suction strainer is installed probably the pressure drop too high

we encountered this in Gelang Patah , a booster pump was added to over come the pressure
drop of suction strainer

b) if pump has been running for sometime in good operating condition, mostly likely is

1) suction strainer clogged

2) If taking media from a slurry tank , check the tank bottom
   Slurry like bleaching earth has dried up and clogged the tank outlet

Some time simple things but poeple tend to look at the pump as a problem

Our Mr How has many years of site trouble shooting experience