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.
 
   


FAMILIARIZATION
Main Menu
Explanations
A through F
More explanations
"Controllers" of
Pulsation

Synopsis overview

CATALOG
CONTACT US

LDi Catalog Printable PDF P4, P5, P6, P7, P8, P9

Familiarization
THE DANGER IS THAT THE PIPE SYSTEM WILL GENERATE A FREQUENCY THAT AMPLIFIES. THE SPEED OF THE FASTEST PROJECTILE, IS HALF-
2,800 Feet per second, 855 meters per second

1. Find the effective compressibility for the system.
2. Determine the speed of pressure transfer for (1) "softness".
3. Feet per second or Meters per second = Frequency/Hz.
  feet pipe run meters pipe run

4. Compare System Hz. with pump Hz. and Pipe XY&Z natural shaking Hz.
5. Where there is coincidence, or at a power of, any of them, at any temperature, or for any one modal length, your pipes are a problem

- THE SPEED OF PRESSURE TRANSFER IN A COLD LIQUID DE-GASSED IN A HARD PIPE
5,600 Feet per second, 1,700 meters per second.
Rate of Pressure Transfer aka "acoustic velocity"

EASY TO PROVE Change the pressure, measure it a mile away a second later.
BUT YOUR FLOW RATE IS BETWEEN 3ft/sec & 25 ft/sec. SO FLOW FLUCTUATION COULD BE ADDRESSED WITH A BOTTLE ON A "T".
PRESSURE IS 250 + TIMES FASTER THAN FLOW -SO:
Pressure pulsation can not be addressed without INTERCEPTION.

 




It doesn't matter how much you have to begin with, what counts is how much the system turns it into.
LARGE PIPE - WITH NO DELTA "P", DO NOT SCRUB OUT PRESSURE WAVES - ARE POTENTIAL AMPLIFIERS.

TOP OF PAGE

 


LDi Page 5

PULSE INTERCEPTION plus FLOW FLUCTUATION REDUCTION
Or just use one of our connections, if all you want is volume accumulation.
Then save a "T" , and use the second connection for flush, drain, relief valve, or the Pl tap.



IT'S TOO SIMPLE, TRYING TO PASS THROUGH A SUDDEN INCREASE TO A LARGER *
DIAMETER DAMPENS HIGH FREQUENCY PRESSURE PULSATION
(* large relative to system pipe diameter)

PRESSURE WAVES GO 500mph IN HOT GAS, BUT TRAVEL 3500mph IN COLD LIQUID.
A "T" PIECE COULD NOT INTERCEPT THEM.

TOP OF PAGE



LDi Page 6


TRUTH PROOF about DISCHARGE PULSATION
Pipe systems cause pulsation. Hard systems destroy pumps.

Same Pump, NO PULSATION
Same Pump, LOTS OF PRESSURE PULSATION

Pumps make flow fluctuations, Systems convert them to pressure pulsation.
As truth is defined by "what if-what if not" you proved to yourself that: pipe systems make pressure pulsation.

When we were seventeen and could run a 1/4 mile in 60 seconds, our pumps could work, because our veins and arteries were soft and "dilatable".

When we die in bed with out boots on, and the quack say "of natural causes", his pronouncement is simple that our "pump" was tired BECAUSE OUR "PIPES" BECAME HARD.


Restrictions make systems "hard" HARD SYSTEMS KILL PUMPS

TOP OF PAGE


LDi Page 7

PULSE DAMPENING - INFESTED WITH "WITCHCRAFT"?
How much pulsation was there before the "Damper" was fitted?
- And how much after fitting the single connection "DAMPER".
It can be impossible to know, without data capture at kHz and very fast response characteristic transducers.
? CAN A HUMAN EYE SEE ABOVE 30Hz., A 20ms RESPONSE GAUGE, MEASURE A 1450 meters/sec PRESSURE PULSE GO BY?

SPRING WEIGHT
HOW FAST THEY SHAKE, HOW FAR THEY SWING DEPENDS ON THE WEIGHT & THE SPRING - NOT ON WHAT EXCITES THEM.

EIGHT GAUGES CONNECTED TO THE SAME POINT AT THE SAME TIME, WHICH TO BELIEVE?

 
WITH GLYCERIN
AND CHOKE
WITH GLYCERIN
NO CHOKE
NO GLYCERIN
BUT WITH CHOKE
NO GLYCERIN
NO CHOKE
GAUGES CONNECTED THROUGH A CAPILLARY
GAUGES CONNECTED THROUGH A 1/2" PIPE

TOP OF PAGE

 

LDi Page 8

SUCTION SIDE PULSATION
The Problem Absorbed Air or Gas
"Started" for Recip. Pumps means each suction stroke.

When a pump is started, there is an instant pressure fall at the pump end of the system.
Unless intercepted, a negative pressure wave travels back up stream to the point of supply.
The sudden pressure reduction causes gasses to come out of solution. They form bubbles which join, then act as springs, between slugs of liquid.

The slugs are excited into oscillation by the rebounding negative wave. The slugs then alternately slam then starve the pump suction. The higher the pressure the harder the slam.

AIR / GAS OUT
OF SOLUTION

Excited mass
oscillation between
two springs

If the pump has suction check valves 2, they are knocked open when they should be closing. See "VE" below.

MASS
VELOCITY

THE FORCE FROM THE MASS VELOCITY OF THE SLUGS IS MORE THAN CHECK+SPRING

VOLUME IS GOOD, FORCE IS BAD
DO NOT INCREASE FORCE/PRESSURE

When you are thirsty, you lift and pour the liquid in, you don't force a pressurized hose down your throat!
The biggest enemy of good volumetric efficiency for a recip. pump, swiss replica watches is too much pressure on the suction side.

"VE" Volumetric efficiency falls, and pulsation shakes the pipes.
Which causes even more PRESSURE PULSATION
.

See Page 8 item A

TOP OF PAGE

LDi Page 9

SUCTION SIDE PULSATION
The Answer 2 DO's and 2 DON'Ts

"Started" for Recip. Pumps means each suction stroke.




LOCAL SUCTION VOLUME ELASTICITY IS AN ESSENTIAL.


2, Do not insert orifices or restrictions,
they will cause wave rebounds at a higher frequency, and cause frothing (4).

 
www.Liquid-Dynamics.com
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 rolex replica devices can be obtained from our associate websites:


PulseGuard Inc., and Ltd. for further information about pulsation dampeners / pulsation dampers.
Pulsation-Dampeners.com - Pulsation Dampener
PulseGuard.com - Pulsation Dampeners
PulseGuard.co.uk - Pulsation Dampers
PulseGuard für Deutschland - Pulsationsdämpfer
Shock-Guard.com and ShockGuard.co.uk to find large gas bag vessels, jumbo bladders, float separator / big bellows type pipeline shock attenuators and expansion / contraction volume compensators, surge alleviators, and shock alleviators.
Shock-Guard.com - Surge Alleviators
ShockGuard.co.uk - Shock Alleviators
Accumulators-Hyd.com and Accumulators.co.uk for information about energy saving in pumping systems, standby emergency power, safety shutdown systems, hydraulic accumulators, and hydropneumatic accumulators.
Accumulators-hyd.com - Hydraulic Accumulators
Accumulators.co.uk - Hydropneumatic Accumulators
In recent years, the United replica watches uk States has repeatedly to the East Asian region rolex replica additional aircraft carrier. The largest one was the replica watches end of 2010, when the bombardment of Yin Ping Island, the situation in North Korea in a state of explosive, the United States has urgently deployed "Reagan".
Flow-Guard.com to find protection against excess flow. Guard against toxic spills when pipes burst, guard against gushers and fluid loss when hoses split, Flow-Guard guards against excess flow floods with flow fuses and breather bags
Flow-Guard - Flow Fuses and Breather Bags


Liquid Dynamics