Vertical mixed flow turbine pump selection
Vertical mixed flow turbine pump selection
(OP)
Hello Experts,
We are planning to buy and install VT pumps (seawater &15,0000 m3/hr capacity)through design and build contract. I would like to know the best practices in this field and the best brands and designs for the different parts of this pump.
I would like to know also the important stages in manufacturing these pumps and how to control quality.
This is the first time for me to buy this size of pumps and I will appreciate your assistance.I am hesistating to hire a consultant as I have some limitations.
Regards
We are planning to buy and install VT pumps (seawater &15,0000 m3/hr capacity)through design and build contract. I would like to know the best practices in this field and the best brands and designs for the different parts of this pump.
I would like to know also the important stages in manufacturing these pumps and how to control quality.
This is the first time for me to buy this size of pumps and I will appreciate your assistance.I am hesistating to hire a consultant as I have some limitations.
Regards





RE: Vertical mixed flow turbine pump selection
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Vertical mixed flow turbine pump selection
RE: Vertical mixed flow turbine pump selection
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Vertical mixed flow turbine pump selection
Anything else just pits or gets eaten in a very short time.
Unfortunately your comment "I am hesitating to hire a consultant as I have some limitations." usually means you or your boss is trying to do this on the cheap by using inexperienced junior engineers such as yourself. What are your "limitations"??
This is a serious and significant error and you will end up making some big mistakes which will cost far more than employing a consultant engineer with years of experience of such pumps and motors. You can't get what you need from the internet.
Look closely at the casting of the impellor and the QA associated with that. That's where the big issues happen.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Vertical mixed flow turbine pump selection
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Vertical mixed flow turbine pump selection
It is only one pump to be added to the manifold and I don't think need consultantndue to cost and scarcity of qualified consultants in my part of the world
RE: Vertical mixed flow turbine pump selection
You said "This is the first time for me to buy this size of pumps ", therefore we could only draw the conclusion that your experience in this area was limited.
Like I said - when cost stops you hiring experienced people to do work then expect more costs when it goes wrong.
I work on projects all over the globe as I'm sure many of the others on here do as well, so scarcity is not an excuse.
Do a search on this site for "vertical turbine pumps" and you'll find a lot of the information you are looking for. Go look at vendor websites and download their guides and brochures and do a comparison.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Vertical mixed flow turbine pump selection
Contact the previous supplier / pump manufacturer or search the website of the major pump manufacturers - it's not rocket science.
Of course what you have highlighted is a complete lack of useful data with your original post for a pump unit that will be a minimum of something like 1700 KW drive.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Vertical mixed flow turbine pump selection
Then you're good to go. Why mess with what works?
RE: Vertical mixed flow turbine pump selection
If a duplicate is not available or the user is not satisfied with existing, that may build a case to get a new one.
Issues:
Materials: it depends on where in the world these pumps are as to material selection; different temps and salinities require different materials. Nickel aluminum braonze is probably the most used material for seawater but duplex stainless costs constantly fluctuate and can be a better option. Ask a metallurgist familiar with your area.
Construction: You are on the border of a mixed-flow design; usually up to 100-120 ft head. Check these out online.
Lineshaft and bearing configuration:
Is this deep-sea or near shore;i.e. is there much sand in the content? If so, you really need to look at bearing/lineshaft design. With any sand you should have enclosed lineshaft with a good "sand" or bottom bearing. You will also need to consider how to lubricate enclosed bearings, again especially the bottom bearing.
How long will the lineshaft/column section be? Sounds like shortset ( <10') If so make sure everything is SS, flanged and SS bolting.
As far as manufacturing, checking the impeller casting certs could be important, as well as for balance. Will you go with just bowl rings, or both bowl and impeller?
So many more things to go through before making a prudent selection. This is why it is not a good idea to try to design one of these on the internet. If you are not going to consider a consultant, talk to a reputable manufacturer and get their opinion. Most of them don't bite.
RE: Vertical mixed flow turbine pump selection
We have three pumps already on the same manifold and after several years we wish to install additional one.Of course, I have all information of previously installed pumps and feedbak of the operator. I am just writing in this forum to get more advises and may be an update about latest designs or technologies. I didn't write here to get scolding.
Nevertheless, many thanks to whoever replied to my post.
I really appreciate DubMac who invested his time in writing good advise and recommendations. Thank you DubMac.
RE: Vertical mixed flow turbine pump selection
You may be right - we were being a little obtuse, but to avoid it the next time, I would recommend the following:
1) Make it clear in your OP what your situation is and why you are looking for information
2) Do some work beforehand to investigate or search for information. E.g. in your case you could have said, "Our current pumps are made by "X", I have also found similar pumps made by "S", "T" and "G". Are there others worth considering or any feed back on experience of those vendors would be very useful". There are a lot of posts here which are very broad and say things like, "please teach me all you know about pumps". Far far too broad a subject for an internet forum
3) Be as precise as you can and give as much information as you can - you were ok in terms of flow and head, but location makes a difference
4) remember all the posters do this for free and in their spare time, so cut them a little slack.
Hope you got a bit of useful information, but if you get something a bit more specific, come back and also let us know what you chose / did afterwards.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Vertical mixed flow turbine pump selection
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Vertical mixed flow turbine pump selection
Copying an existing pump can also be a recipe for disaster if you have not checked the hydraulics on the system
I think what is irking everyone here is that it is perceived that you (and your superiors) have no engineering experience and you are asking experienced engineers on this forum for advice to minimize costs by doing it yourself. It is like you asking a bunch of doctors for tips on how to do a heart transplant by yourself because your neighbor had one done on him and it was successful. There is more to it than meets the eye and because of the ramifications nobody wants to get involved with you. You have to have some basic knowledge of pumps to gain from the benefits that this forum can provide. I could be wrong but it seems clear that you do not even have the basic beginner’s knowledge of where to even start. I truly hope I am wrong in what I said. Good luck
RE: Vertical mixed flow turbine pump selection
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RE: Vertical mixed flow turbine pump selection
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)