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

LDi - P18

To understand the normal pulsation signature of the triplex test shown here it is necessary to examine the plunger and valve motions that cause the mass transfer velocities, before study of pressure response plot A. & discharge plot B.

Strokes of a triplex piston pump displacement or forward stroke, suction or backwards stroke

Pressure generation against system resistance inside the plunger chamber

Suction check valve stroke, note the opening delay of 28 ms during the decompression of the red
cylinder

Suction mass flow kg per second caused by pressure difference, supply line to in pump cylinder

Suction system pressures excited by the velocity jump from valve delay and mass oscillation

Discharge check valve movement, note the overshoot and rebound, indicating valve stop allowing
more than 25% of critical diameter travel.

Discharge mass flow from the individual cylinders, then combine for theoretical steady state.

Discharge pressure at check valve outlet, response to mass decompression explosion and
Joukowsky shock. Note: Log scale change - otherwise shock amplitude would take the entire
page.

Individual dampers per cylinder, note stiff “FlexFlon” membrane stroke response to high
frequency pulsation