SMART Principles to Troubleshooting (pump case #2)

Another ...

Study Case: Centrifugal Low Head Pump (horizontal shaft)

Symptom: a pump cannot deliver water steadily

the team did:?uSer &?Modular:?SMART?approach:?

1.uSer - blackbox perspective; they studied the overall integrated system as a whole - what it does. Pump has to suck & discharge consistently but they found a pump cannot deliver water steadily.

2. Modular functioned view & Analyze; observation: only 1bar max discharge pressure (& diminished gradually) & hot discharge line. When suction line primed with additional water discharge pressure increased but diminished when the water priming stopped.

The analysis: hot discharge line has not enough water flow to cool down the line: have some vacuum due to rapid velocity - rushing high volumetric flow inside small diameter of suction line

The root cause suspects: high suction line's pressure drop: the suction pipe is small & long

3.Replace & reassembly (gRounded approach)

a. increase the suction line 0.5" more than the suction flange dia. size --- ensure enough diameter to accommodate high volumetric flow

(suction horizontal portion pipe also slightly inclined in such a way to ensure flooded (free-flow-gravity-assisted) head to impeller)

b. put water level switch --- reduce sediment flow into suction line & maintain enough suction head

4.Testing & observe; they tested on the response of the system: has been consistently run, now with 2.6bar discharge pressure (was less than 1bar)