×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

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!

*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

Centrifugal pumps flow limitation

Centrifugal pumps flow limitation

Centrifugal pumps flow limitation

(OP)
Hello everyone
In our project specification we required API 610 centrifugal pumps for condensate.
having these parameters:
Flow 0.7-0.8(m3/h)
Suction pressure: 2.2 bar
Discharge pressure: 35.8 bar

The contractor claimed that there is no centrifugal pumps available on the market that can operate in these parameters, hence he proposed double diaphragm pumps.

what are your thoughts?

RE: Centrifugal pumps flow limitation

The only centrifugal I can find that will do that is a submersible. A Grundfos 5S30-48, 3HP will do that. You can install it in a wet well, or it can even be put in a can and used as an inline booster.

RE: Centrifugal pumps flow limitation

(OP)
Thank you Valvecrazy for your response. however the condensate pumps is going to be installed after a pressure vessel "where the condensate will be stored" so the submersible pump is not an option.

RE: Centrifugal pumps flow limitation

A submersible in a can can take some inlet pressure. How much I don't know. Good luck!

RE: Centrifugal pumps flow limitation

That's a pretty small flowrate at quite a large differential pressure, so you're getting into the realms of small PD pumps of some sort.

If this is after a separator and your "condensate" is volatile, your issue is going to be NPSH or the lack of it...

A can pump might be your only solution.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Centrifugal pumps flow limitation

API 610 is out of the question, therefore you need to get the specification reviewed and rewritten by the authority who wrote the spec.
Rotojet pump could be an alternate selection, or as valvecrazy has pointed out a can mounted submersible unit or even mounted directly thru' the wall condensate storage vessel.


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: Centrifugal pumps flow limitation

(OP)
the fluid is Natural-gas condensate, also called natural gas liquids and not water condensate

RE: Centrifugal pumps flow limitation

Then your issue is NPSH.

Condensate is basically at its vapour pressure at 2.2 bar so if you need to pump this then your only way to get NPSH is with gravity. Unless your separator is mounted 5m in the sky, then you need to dig a hole and drop a can unit in or a bigger hole and mount a pump down inside the big pit.

Your issue here is the flow rate. Is it really only 0.8 cubic metres an hour?? That's peanuts.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Centrifugal pumps flow limitation

Any more surprises?

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: Centrifugal pumps flow limitation

(OP)
Thx for your responses. @ Littleinch Yes, the rated flow is 0.9 m3/H and it will operate in the range of 0.6-0.7 m3/h. As I understood, the solution is to raise the height of the vessel and use a can pump or use the positive displacement pump.

RE: Centrifugal pumps flow limitation

Or look at Rotojet or similar?

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: Centrifugal pumps flow limitation

(OP)
thank you for all for your responses.
can you show me a drawing of where to place the can pumps and how it will be isolated and removed in case of maintenance.

RE: Centrifugal pumps flow limitation

Can pumps are simply a vertical turbine pump which is fitted inside a long tube or "can" which is normally just buried in the ground. The pump can be lifted out of the can by simply unbolting the top flange.

You usually need to make sure the outside of the can is well protected and in some locations they insist on a double skin to the tank the same as buried tanks to ensure no leakage.

Just google "Can pumps" for more info.
The dimension Z below is the lowering of the inlet for NPSH purposes from the visible above ground section.

This is still a very small pump. You may need to get a bigger pump and operate it on an on/off basis by storing fluid inside the separator until it needs to be pumped out.

PD pumps generally have a lower NPSH, but still have some and also they can suffer from acceleration head requirements, so they aren't always a good choice for low NPSHA fluids.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Centrifugal pumps flow limitation

(OP)
Thx you LittleInch for your clarifications. God bless you

RE: Centrifugal pumps flow limitation

You can also use a submersible is a can similar to that. The submersible I referenced will work at 3 GPM. I don't think you can get a canned turbine to go that low of a flow rate.

RE: Centrifugal pumps flow limitation

(OP)
@ Valvecrazy
I don't think the referrenced pump will do the work. the differential head we have is 537m

RE: Centrifugal pumps flow limitation

head was 35.8 bar - now its 537 metres ??????????????????????????????

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: Centrifugal pumps flow limitation

That's about right. This is pretty light HC, probably about SG of 0.6.

Still a very small amount of flow so I would batch flow it myself.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Centrifugal pumps flow limitation

NO won't work at 537M, but would work at 35.8 bar.

RE: Centrifugal pumps flow limitation

LI, correct, I'm only haff watching this one and old age got the better of me - forgot the low SG, my excuse anyway.

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: Centrifugal pumps flow limitation

The flow appears extremely low. The hydraulic power we are talking ~700 Watt ?

By the way, just curious, what is the use of pumping condensate (as defined) as such relatively elevated pressure?

RE: Centrifugal pumps flow limitation

(OP)
@rotw To inject it as a fuel with natural gas in a gas turbine

RE: Centrifugal pumps flow limitation

You may want to check this link for example, or try similar suppliers:
https://www.hydra-cell.co.uk/5264-/HydraCell-TSeri...
If the duty works out (concerned by the low flow), you may not get one to API610 but at least to API (for instance API-674).
Due to gas turbine application, you may increase reliability/availability by sparing the pump e.g. 2x100% (if not already done).
You could ask contractor who proposed double diaphragam pumps to substantiate the proposal and especially provide a reference list from proposed vendor (i.e. booster pump for gas turbine application).

RE: Centrifugal pumps flow limitation

You might be much better off looking at chemical injection pumps or dosing pumps at that sort of flow.

Some sort of multi-cylinder piston pump could quite easily do your duty as simple package.

Why the insistence on a centrifugal?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Centrifugal pumps flow limitation

Centrifugal pump is not suitable for your specs, the minimum flow rate of a centrifugal pump is at least 2-3 m3/h.

Before you choose the type of the pump, you need figure out the following(personal suggestions):

1. is the liquid corrosive or not? what is it?
2. is the liquid contains solid particles or not? if there is, how much diameters of the particle
3. you have to consider how to install the pump before choosing one, is it vertical or horizontal, if you are in design stage, then only if the pump parameters can match your condition, you can choose freely, if you need to replace one, then the site condition you need to consider
4. is it outside or indoor installation? is it under normal atmoshpere as it is related to the suction height(NPSHa),if not, you have to calculate it
5. each type of the pump has its pros and cons, centrifugal one, diaphragm one, canned one, metering one,piston one, you need learn which one is the most adaptive

Flow 0.7-0.8(m3/h)
Suction pressure: 2.2 bar
Discharge pressure: 35.8 bar

the diff. pressure is 33.6 barg and the flow rate is this low, I suggest you can choose from high pressure piston pump

hope this is helpful for you

RE: Centrifugal pumps flow limitation

(OP)
@littleInch for maintenance. Now after seeing all of ur responses we will go for a positive displacement pump. Thx all for ur helo.

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! Already a Member? Login


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now