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17.8.15
3.5.15
12.6.14
Using the same Gear Pump for different Media Viscosity
The discharge capacities varies with media viscosity
Example a Gear pump rated to achieve a 3 m3/hr at 200 rpm with media of 3500 CP, if used
for pumping water ,you may get only 0.50 m3/hr or even lesser with the same speed depend
on operating pressure .The higher the delivery head , the higher the hydraulic slip
This is also the same as Rotary Lobe Pumps
This is due to hydraulic slip internally , as water is very low viscosity it tend to slip out between
the gears and only a small percentage of it will be discharged. It also depend on he back
pressure from the piping system
Using low viscosity for metering purpose , a progressive cavity two stage will be bettet option
or High precision Gear Pump which is costly
A reciprocating piston /plunger pump may also be used
Example a Gear pump rated to achieve a 3 m3/hr at 200 rpm with media of 3500 CP, if used
for pumping water ,you may get only 0.50 m3/hr or even lesser with the same speed depend
on operating pressure .The higher the delivery head , the higher the hydraulic slip
This is also the same as Rotary Lobe Pumps
This is due to hydraulic slip internally , as water is very low viscosity it tend to slip out between
the gears and only a small percentage of it will be discharged. It also depend on he back
pressure from the piping system
Using low viscosity for metering purpose , a progressive cavity two stage will be bettet option
or High precision Gear Pump which is costly
A reciprocating piston /plunger pump may also be used
Expect the Unexpected inTrouble Shooting
Share with you as follow
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
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
12.5.14
28.3.14
IMO Triple Screw ACF Series PUMP ~PALM OIL REFINERY
This IMO AB Pumps ACF series has been running for about 30 years and still running
Oldest pump was from 1954 operated till 2006 .Installed at Crude Oil Refinery in Port Dickson
Application Include
Lubrication , Transfer , Loading and Unloading
Industry
a) Palm Oil Installations
b) Steel Mill
c) Power Plant
d) Oil & Gas
e) Cement Plants
f) General Industry
Pumps are ruggedly built to last and require minimum maintenaance
Checked aorund and we found many obsolete models installed about 30 years ago during
early stage of our Malaysian Palm Oil Development are still in operation condition
16.5.13
Metering Pumps _ High Suction Head and High Vacuum in Delivery Line
There was installations where the suction head is higher than delivery head and
or delivery line under high vacuum
This causing syphoning , and flowrate will not be be accurrate , often very much higher than
set at the Metering pump .
Solution
a) Installing a back Pressure Valve
b) pressure loading valve
or
c) Installing a Pressure relief valve to the Pipeline or vessel under high vacuum
This (c) is the simplest cost effective solution
or delivery line under high vacuum
This causing syphoning , and flowrate will not be be accurrate , often very much higher than
set at the Metering pump .
Solution
a) Installing a back Pressure Valve
b) pressure loading valve
or
c) Installing a Pressure relief valve to the Pipeline or vessel under high vacuum
This (c) is the simplest cost effective solution
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