Piping cautions for high velocity seawater
Piping cautions for high velocity seawater
(OP)
Hi,
I am going to start piping for a project for which I found following details in process calculation sheet:
seawater intake; pipe size 24"; velocity inside pipe is more than 25 meters per second.
temperature is 30 Celsius. material is going to be super duplex or some other exotic expensive material.
Above is the maximum pipe size so if I know answers for this I would be able to manage others.
Please tell me if because of high velocity I have to apply special techniques in piping or if certain pipe routing practices are to be avoided.
And NPS 24 pipe routing is new to me. What are things to consider.
Your experience and knowledge would be beneficial.
Thanks.





RE: Piping cautions for high velocity seawater
Check with Process guys - maybe they just forgot to type a dot between 2 and 5 in the velocity number.
Dejan IVANOVIC
Process Engineer, MSChE
RE: Piping cautions for high velocity seawater
[img https://books.google.com/books?id=qTfNZZRO758C&...]
http://www.stainless-steel-world.net/pdf/11003.pdf
RE: Piping cautions for high velocity seawater
RE: Piping cautions for high velocity seawater
RE: Piping cautions for high velocity seawater
The project is going to be one of the largest so there is big flow however mentioned velocity has to be checked.
Process Engr. will be available after a week and i will update you guys about his response.
RE: Piping cautions for high velocity seawater
RE: Piping cautions for high velocity seawater
MJCronin
Sr. Process Engineer
RE: Piping cautions for high velocity seawater
RE: Piping cautions for high velocity seawater
That is some flow rate.
This is far too high a flowrate to be economically feasible or practical.
Even super duplex will suffer erosion and stripping of the corrosion resistant layer at that speed.
will be interesting to see if this becomes more realistic.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Piping cautions for high velocity seawater
At 8m/sec, dp = 2.4psi/100ft.
It may well be that the process engineer is trying to maximise on the capabilities inherent with 25Cr superduplex, but unit pressure drop, high momentum stresses on piping supports (rho-v2 = 625e3 >> 200e3 in SI units) and probably water hammer also might get in the way.
RE: Piping cautions for high velocity seawater
RE: Piping cautions for high velocity seawater
Go back and check decimal points.
RE: Piping cautions for high velocity seawater
However the hp required to move that much water is another issue. If this line is longer than a few feet the pressure drop would be huge.
And the reaction forces at an elbow or the closing of a valve would be difficult to handle.
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube
RE: Piping cautions for high velocity seawater
If this system is ever actually built it will be a giant energy waster....
How much longer will it be before we, once again, find out that this is a mistake or typo ?
MJCronin
Sr. Process Engineer
RE: Piping cautions for high velocity seawater
???
Just needs a larger intake diameter.
RE: Piping cautions for high velocity seawater
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Piping cautions for high velocity seawater
Reviewing of the post shows that this application is a seawater intake. Although, the particular type of seawater intake is not specified.
The typical seawater intake is gravity flow with a velocity of around 0.6 m/s. Multiple pipes are used.
The recommended material for this type of gravity flow system is HDPE, because the low velocity will cause corrosion problems with most metallic piping materials.
A velocity of 25 m/s is probably not realistic for any type of seawater intake.
RE: Piping cautions for high velocity seawater
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Piping cautions for high velocity seawater
RE: Piping cautions for high velocity seawater
That's a bad sign. By the next time they log in, they could already have this pipe on order
RE: Piping cautions for high velocity seawater
RE: Piping cautions for high velocity seawater
Best to you,
Goober Dave
Haven't see the forum policies? Do so now: Forum Policies
RE: Piping cautions for high velocity seawater
I read just a few years ago in an article in "WaterWorld" by Mr. Allan Budris the statement, "Furthermore, the suction piping should be at least as large as the pump suction nozzle and be sized to ensure that the maximum liquid velocity at any point in the inlet piping does not exceed 8 ft/sec." [This in case the OP comes back and this wasn't just a "hit-and-run poster", or scared off by now!]
All have a good weekend!
RE: Piping cautions for high velocity seawater
But not from a 24" pipeline I hope.
RE: Piping cautions for high velocity seawater
It came out that velocity shall be much lower as mentioned by many people in this forum. It will be 3.5 m/s
RTR pipe material will be used and pipe size will also be very large.
Thanks everybody.
RE: Piping cautions for high velocity seawater
Piping Design Central