×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Weir installation on sea water network

Weir installation on sea water network

Weir installation on sea water network

(OP)
Hi
Is there any one to has experience of weir installation citeria on sea water net work,my means when weir should be installed in ney work? and is it possible to consider vacuume breaker instead of weir? I will be thanks to reply me as soon as possible.

Best regards


 

RE: Weir installation on sea water network

A weir can be installed to make sure that the topmost exchangers in the system are always filled with water. This however means that your weir should be as high as the elevation of the highest exchanger in the system. Another way to ensure positive pressure at the highest exchanger is a backpressure valve. You will need some protection like a vacuum breaker for the case that the valve gets stuck or opens inadvertently, and you lose backpressure in the system.
The alternative is to make the return line self-venting, with the vent point at the highest exchanger. You'll need to size the return line for that (it usually becomes bigger). All this can be fairly easily computed using Bernoulli's law.
So if the highest exchanger is 20 m above the return point, and you want 1 bar overpressure after the exchanger, you will need a backpressure valve that drops 3 bar. Note that seawater usually contains dissolved air, which will come out of solution when the pressure is dropped. The valve and support design should take this into account (vibrations).

Cheers,
Joerd

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

RE: Weir installation on sea water network

A vacuum breaker will not last long in a seawater system, given the susceptibility of its moving parts to corrosion, silt, and barnacles, among other things.  I'd use at least three, if someone held a gun to my head and made me use any at all.

Use a weir or a standpipe.  It has the ideal number of moving parts; none.  And it will still require replacement, eventually.



Mike Halloran
Pembroke Pines, FL, USA

RE: Weir installation on sea water network

(OP)
Joerd,thanks for replying to me.

There is one point for me.where the return line should be connected ,inlet or outlet of heat exchanger,I think to outlet line of heat exchanger.In this case it seams pressure drop of back pressure valve should be considered 1 bar.Please clarify.What is difference between self-venting line and vacumm breaker valve operation in this case.

Thanks again

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources