Liquid Dynamics International Ltd. - Piping System Analysis / Piping System Simulation

LDi – P22

Example: Suction pressure too high. Driving the pump, instead of it "doing its thing"

You have the hardware already? LDi has the tools
Certified calibrated signal conditioned transducers
Real time massive paper rate, oscillograph printers
GPIB data stream capture laptops, with FFT analysis
Yes even stethoscopes! Let us identify the heart of the problem on site.

"Joukowsky" velocity jump, excites RV.

For more on the example please see LDi Pub. 1 page 7
The answer is simple, as usual it’s the pipe,
it is stopping one cylinder filling – too long.

For more on the "manifolding" examples, please see LDi Pub. 5 page 34 and 35

We will survey your pumping system pipe and advise where:
1. They are oversized
2. Direction changes are causing instability
3. "T’s" & "Hard 90’s" need replacing
NO = RPM doubled from 1950’s design, valves driven off seats by suction column oscillation
YES = Stop valves from "talking" to each other.
NO WAY = Typical manifold, turns pulse into an "orchestra"
YOU BET = intercepts

Then job 1 becomes identify the pulse signature please see LDi Pub. 2 pages 16 and 17

Note: The problems shown above are not a pump vendor responsibility. In all cases they were failure by the engineering contractor to consider pipe system reaction to mass transfer velocity change.