velocity of sea water in pipes
velocity of sea water in pipes
(OP)
Hi,
what value of velocity for sea water piping i should take for sizing a network to feed 8 heat exchangers all over a plant.
literatures give diffenet values
what value of velocity for sea water piping i should take for sizing a network to feed 8 heat exchangers all over a plant.
literatures give diffenet values





RE: velocity of sea water in pipes
For a properly designed piping system, the desired velocity range depends on the piping materials, temperature, coatings, interior roughness etc
Can you tell us more about the piping system and the service....????
Desired velocities for FRP are significantly different than for Titanium
Eight heat exchangers, you say......hmmmmmmmmmmmmmmm?
"All over the plant"........hmmmmmmmmmm..???
-MJC
RE: velocity of sea water in pipes
"Less than 1% of the energy moving a car goes towards the driver."
Amory Lovins - The Oil End Game http://virtualpipeline.spaces.live.com/
RE: velocity of sea water in pipes
what material is to recomand for a sea water piping, vélocity.
sea water T = 25°C
air T = 45 °C.
T max at the exchangers inlets <= 28.5 °C
thank you
RE: velocity of sea water in pipes
D<2" ==> 1.3 m/s
3">D>6" ==> 2.5 m/s
8">D>18" ==> 3.5 m/s
D>20" ==> 4m/s
but this book is very old I want to confirm these values?????
thank you
RE: velocity of sea water in pipes
The book might be considering those aspects using some given acceptable pressure loss for the "average" system.
For sizing a system, I would use a velocity that will not be too sensitive to waterhammer effects from closing valves, getting a relatively conservative diameter and not worrying too much about erosion, which shouldn't be too bad at 4-6 fps anyway, if sea water intake is not picking up too much sand, and if it is, use an interior coating.
You may be able to go to higher velocities, say 10 fps (3m/s) or even higer, if you want to take more chance and possible expense on mitigating water hammer effects and can handle a greater pressure loss in whatever length of pipe you have.
"Less than 1% of the energy moving a car goes towards the driver."
Amory Lovins - The Oil End Game http://virtualpipeline.spaces.live.com/
RE: velocity of sea water in pipes
RE: velocity of sea water in pipes
here you can find a table with suggest velocity limits:
http://ww
MATERIALS SELECTION FOR HIGH RELIABILITY COPPER ALLOY SEAWATER SYSTEMS
http://w
S
Corrosion Prevention & Corrosion Control
RE: velocity of sea water in pipes
For example 1000 USGPM -
6" ' ' ' = 11 ft/sec
8" ' ' ' = 6.5 ft/sec
10" ' ' ' = 4 ft/sec
For my thinking, selecting on velocity alone is not always the best solution, you need to consider the overall economics factoring in total head loss which reflects in the pumping costs, pump, pipe and valve costs, handling and installation, life of the pipeline(wear) etc.
There is really no problem with velocities at the higher end if the product is clean and friction losses are within manageable limits.
This is what BigInch has already pointed out and is normal practice when selecting pump systems:-
"BigInch (Petroleum) 12 Nov 08 14:12
Really you should determine the optimum pipe size based on energy cost of the head loss you get with each diameter and the cost of providing that head by running some kind of pump plus the cost of providing each pipe diameter."
RE: velocity of sea water in pipes
10 years operating at the wrong BEP and pipe diameter can easily buy you a new pipeline.
**********************
"Pumping systems account for nearly 20% of the world's energy used by electric motors and 25% to 50% of the total electrical energy usage in certain industrial facilities." - DOE statistic
"Note: Make that 99.99% for pipeline companies" - http://virtualpipeline.spaces.live.com/