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Head loss, surge pressure

Friction losses

Volume inefficiency

Velocity jump shock

Nomogram Frequency vs. Pipe ID


LDi Catalog Printable PDF46

Check the amplitude of any highly excitational pressure spikes
In pump literature a.k.a. "Velocity Jump" causing "Joukowsky shock"

amplitude of highly excitational pressure spikes
You can reduce "Velocity Jump Shock" to a generally insignificant figure in 4 simple steps:
1. Select a dampener with an ID 12 times the diameter of the inlet connection. 2. Have an outlet 1/2 the area of the inlet. 3. Increase the volume by 3 times the inefficiency. 4. Decrease the cushion pre-fill pressure proportionately to the volume increase, from 80% of system pressure to as low as 50%.

The combined effect of mass acceleration, velocity jump, pressure wave acoustics, fittings and pipe resistance all in a time dependent frame, along with valve action, and pump characteristics may be modeled for you by: LDi PulseView software. This is not a free service. Please complete input data set tabulation.


Example: Actual results depend on stroke radius to connecting mechanism length, etc. Flow Velocity for crank shaft angle 180 degrees of pump rotation The velocity to which the liquid has to leap from being static in zero time 3.2 x rated flow @ 50% volumetric efficiency 2.6 x rated flow @ 64% volumetric efficiency 2.175 x rated flow @ 77.5% volumetric efficiency 1.6 x rated flow @ 87% volumetric efficiency 0.7 x rated flow @ 96.68% volumetric efficiency Pressure Time – 180 degrees of pump rotation Velocity Jump Shock Acceleration Head Theoretical steady state pipeline pressure How system pressure reacts Follow the red to green boundary Valve bounce


Pulsation Dampeners at Fluid Flow Control

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