Waterhammer analisys its obligatory ?

[Cesaredu]

There exists any code asme? api?, i know that it depends of the situation, but i would like to know when its extremely necessary, if its critic?

Best regards for all,

Cesar.

 

[dcasto]

you must always check for waterhammer. its simple and easy, so why not do it.

 

[Zapster]

From 2002 version of B31.3:
E) Sources of pressure to he considered include ambient influences, pressure oscillations and surges, improper operation, decomposition of unstable fluids, static head, and failure of control devices.

In my mind it means that if the waterhammer analysis limits/defines the design envelope then it is obligatory.

 

[MortenA]

dcasto

Its not _always_ that simple

Best regards

Morten

 

[BigInch]

May not be sooooo simple, but it is not difficult, unless your client makes it so. Just so happens I have a guy right now that thinks its (botttle) rocket science; specs the pipe length and elevations to the 1/10th of a mm, enters 5000 elevation points on a 100 km pipeline (for that to be accurate you must correct for temperature difference from 60F to the temperature during construction), puts 66 head points on the pump curve and yet doesn't manage to describe the curve out to zero flow, apparently NOT thinking that 8 equally spaced points from 0 to runout will regress a better equation than his 66 points from 0 to BEP.

GIGO pays the bills.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[BigInch]

BTW, these days, as stated above, its relatively easy and the practice has been standardized to such an extent that, if you didn't do it, it just as easily might be considered as malpractice, especially if injury or damage of any kind resulted from what might be any plausible overpressure argument.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[JohnGP]

Just out of curiosity, what are the programs of choice for performing waterhammer analyses? Some (many) years ago I did some work on an offshore pipeline system, but that was with an oil company's inhouse developed program.

 

[BigInch]

Petroleum company favorites are,

Pipeline Studio
Olga2000
Stoner Pipeline Simulator

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[Cesaredu]

There are more:

Hammer Bentley
AFT Impulse

Tnhx all.

 

[LSThill]

Review Hydrocarbon Processing July 2009

Estimate water hammer loads in steam piping
The Problem is more complicated because of the two-pahses flow.

http://www.nxtbook.com/nxtbooks/gulfpub/hp_200907/#/64

 

[BigInch]

It is true that if you enter the 2-phase regime, it becomes instantly more complicated... with any fluid.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[BigInch]

Today they're changing the steady state report because (I found the) pressure increased by 20 psi, over 1133 psig required, due to erroneous elevations being selected from the pipeline elevation profile. It turns out taht they used spot elevations at 0, 5, 10, 20, 30 km, etc. rather than high and low elevations over various segment lengths. (Hydraulics don't give a RA about spot elevations.) But, for a 1.8% error, its really not worth changing the report. I don't know what they'd do, if they had a hot oil line in a winter to summer temperature, wet to dry soil heat transfer coefficient and variable heat capacity environment with a few pipeline shutdowns such that the hydraulics never ever stabilize. Hard to get just one magic number out of a scenario like that.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[Cesaredu]

I found this information, sorry for the traduction



Before a project of a line of pumping to be constructing, how to determine if it is necessary or not to study the transitory phenomena (known normally with the name of "water hammer"?
The first thing that must be done is to calculate the pressure in regime that supports the pipeline.
Then Jucowski's pulse must evaluate of overpressures, that is the maximum value that the same one can adopt. Later, the pressure is evaluated in regime(diet) + - the pulse and is observed if it comes to dangerous values for the break of the pipeline (to see specifications of the same one) or minor values to-6 to-7 m of water column to avoid cavitation in the whole pipeline. Of being near these limits in some case it suits to study with more detail the system