Liquid Dynamics
Pulsation Analysis, Diagnostics, Prediction by Software
Pipeline and Pump user Problem -

Pulsation Analysis, Diagnostics, Prediction by Software

LIQUID DYNAMICS Ltd. offer Pulsation / Vibraton and Shock - Analysis & Diagnostics + Software Models
Please call toll free USA 1-888-326-7377 WE HAVE PEOPLE - Not voice mail. --44-161-480-9625 UK
Fluid Flow Control animations by Liquid Dynamics.

Main Menu

plots A, B, C

Input data for
shock modeling

models relations
7 ocillographic

input data

Equations &


7 Explanations of oscillographic plots & findings
These examples of out put, 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 set to "RECIP-VIEW" piston position.

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.

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.
1. The liquid mass between damper and suction is too long. Slugs are going into oscillation and driving the checks off their seats.
2. Membrane response characteristics of suction damper may be unsuitable for this frequency.
3. Discharge checks may have some overlapping activity, and be exciting suction acoustics.


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.

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.
Pumps 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.
Phone USA 910.270.2737
PO Box 506 Hampstead, NC 28443 USA
UK (for EC) --44(0)161-480-9625
PO Box 47, Stockport, UK SK3-OLH


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. - Pulsation Dampener - Pulsation Dampeners - Pulsation Dampers
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Liquid Dynamics