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MODELING
Pub 4 Main Menu

ShockView schematic

ShockView plots A, B, C

Input data for shock modeling

PulseView models relations

7 ocillographic plots

Necess. program input data

Equations& sources

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7 Explanations of oscillographic plots & findings
 These examples of LDi PulseView output are from a version compiled for a deep sub sea methanol injection system, 6.25 miles (10 kilometers) to the well-head. Flow was generated by a multi-layer diaphragm head pump, against a total system resistance at the pump, of 700 Bar.

To read each set of plot lines, relate each to "Recip-View" piston position.
Recip-View Plot

"Suck. Pres. View"Suction Pressure View Plot
Saving the cost of building a system which malfunctions, by generating an LDi PulseView model first, is only practical, when the necessary investment is made, to collect accurate input data. Please see page 31.

"Suction Valve-View"Suction Valve-View Plot
A. See "Suc-Pres-View", For enough pressure decay to allow the suction check valve to open.
B. See "Recip-View", When Suction Valve should open.
*Any or all of 3 things may be happening:
1. The liquid mass between dampener and suction is too long. Slugs are going into oscillation and driving the checks off their seats.
2. Membrane response characteristics of suction dampener may be unsuitable for this frequency.
3. Discharge checks may have some overlapping activity, and be exciting suction acoustics.
"Fram-View"
Fram-View Plot
The typed notations of on the plots are added to assist in understanding how a pump is affected by all the system parameters.
The response characteristics of diaphragm membranes are generated when attempting to stabilize pump & system.
"Membrane-View"
Membrane-View Plot
In a system with a reciprocating pump, the root cause of the great majority of problems, begin with suction check valve response opening and closing delay. This is always found to be caused by the compressibility, SG, & cP of the system liquid, and the pipe design coming to the pump. The most common problem is too much suction force. Next are oversized suction pipes, and frequently, interaction / interconnection between pumps or between individual check valve pockets. Please see pages 34 & 35.
"Valve-View"
Valve-View PlotPumps make flow, systems make pressure. The inertias in mass transfer are the essential components that require analysis. When the mass dynamics are established, then we examine "acoustic" response - know action, before reaction.

Understanding the effect of pipe design on pump performance will keep systems out of trouble.

 
Suction dampener too far, pressure response of supply pipe system "Suction Valve-View" (destabilized valves) Small diameter stiff on suction diaphragm response to pressure pulsation Discharge dampener, membrane resonance to pressure change Stroke less than 0.25 seat diameter, discharge check valve response
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Liquid Dynamics International provides pipeline and pump user problem analysis, diagnostics, prediction by software, pulsation analysis, piping system analysis, and piping system simulation. For water hammer and shock solutions pulsation dampening and shock alleviating devices can be obtained from our associate websites.

PulseGuard Inc., and Ltd. for further information about pulsation dampeners / pulsation dampers.
PulseGuard. USA: Pulsation Dampeners | Pulsation-Dampeners.com: Pulsation Dampeners
PulseGuard Limited: Pulsation Dampers | PulseGuard für Deutschland: Pulsationsdämpfer

Large pressure vessels, jumbo bladders, float separator / big bellows type pipeline surge attenuators and
expansion / contraction volume compensators, surge alleviators, and shock alleviators.
Shock-Guard. USA: Surge Alleviators | Water-Hammer.com: Water Hammer
ShockGuard.co.uk: Shock Alleviators | Suction-Stabilizers: Suction Stabilizers

Information about energy saving in pumping systems, standby emergency power, safety shutdown systems,
hydraulic accumulators, and hydropneumatic accumulators.
Accumulators-Hyd: Hydraulic Accumulators
Accumulators.co.uk: Hydropneumatic Accumulators | HydroTrole: Hydraulic and Control Engineering

Protection against excess flow. Protect against toxic spills when pipes burst, guard against gushers and fluid
loss when hoses split. Flow-Guard against excess flow floods with flow fuses and breather bags.
FlowGuard: Flow-Guard - Flow Fuses and Breather Bags

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