Pump Efficiency limitation 1

[balasub]

Is there any efficiency limitation / minimum criteria for the Centrifugal pump?

 

[Artisi]

No.
Why or what are you asking?

 

[balasub]

I have received one vendor pump quote stating 11.9% efficiency. So I have clarification, Are there any limitations / minimum criteria for the Centrifugal pump?

 

[NovaStark]

The efficiency would mainly depend on the desired flow rate. So your BEP would tend to closely match the nominal flow rate.

 

[LittleInch]

Is there any efficiency limitation / minimum criteria for the Centrifugal pump?

No, why would there be?

Only whatever you need / desire. Do a life time calculation to see if a more efficient pump which costs more saves you money over say a 5 year period.

That is a pretty low efficiency alright - what is it ? an open impellor waste water pump?

 

[TenPenny]

An efficiency that low implies to me that you're looking at a 'low flow' pump. Some centrifugal pumps have straight radial vanes, like 24 of them, and are capable of very low flow rates, like 1 gpm. Although the efficiency is low, the hp is also low, so the actual amount of power lost to inefficiency is fairly low. These tend to be a bit niche applications, to allow a single stage pump to be used instead of a multistage pump.

For example, look at the Goulds LF3196 series; I've sold those many times for specific applications where the client wanted a single stage pump capable of a low flow rate.

 

[Artisi]

give a bit more detail like flow, head, product and pump in question so people understand what / why you're asking.

 

[balasub]

Medium : HC Condensate, Flow: 6.83m3/h, Head: 54m, Efficiency: 11.6%, MCSF: 1.57m3/h, BEP: 7m3/h, Power: 8.6kW. API 610 Pump. Please let me know if any information required.

 

[Artisi]

As the pump curve isn't attached it will be assumed that the pump is operating very far to the left on the operating curve which explains the efficiency of 11.6%.
If this is the only pump that is capable of the flow and head - that's it.

All you can do is look for an alternate pump / supplier but don't think you will find anything with a higher efficiency.

 

[LittleInch]

Medium : HC Condensate, Flow: 6.83m3/h, Head: 54m, Efficiency: 11.6%, MCSF: 1.57m3/h, BEP: 7m3/h, Power: 8.6kW. API 610 Pump. Please let me know if any information required.

As much as you can give us.

The pump curve, the pump mechanical details or cross section, type of impellor, brand, model, brochure, that sort of thing.

It does sound very low alright, but why an API 610 pump for something like this? seems crazy and might be the reason why.

 

[TenPenny]

This definitely looks like a LF application, so I'm not surprised by the efficiency. What you are trading off is that the efficiency is low, but the shaft stresses are also low, so the reliability will be higher.

I'm assuming that the site requirements for an API pump for HC condensate are the driving factor. I'm pretty sure the refinery in my area would have the same requirements. If you want the operating point to be in the 70-120% of BEP (or whatever that requirement is), then you have very few options.

 

[LittleInch]

That looks like a nominal 30 US gpm to me which has been precisely calculated into m3/ hr.

Low flow for sure and rel low power so all those other losses come round to bite you

 

[georgeverghese]

A quick search on the net tells me you can get a pump running at >60% eff for this operation of 30gpm at 180ft of head. The savings you get on power draw should give you a short pay off duration in case there is any CAPEX disadvantage between this and the pump you've got now

 

[pierreick]

Hi,
1 quotation is meaningless; you need at least 3 proposals to be able to compare offers.
Check with reputable vendors and compare Capex+Opex .

SPA PUMPselector

pump-selector.starpumpalliance.com

examples:

Overhung | Sulzer

ITT Goulds Pumps is a leading manufacturer of pumps for a wide range of industrial markets — including chemical, mining, oil & gas, power generation, pulp and paper, and general industry. | Goulds Pumps

ITT Goulds Pumps is a leading manufacturer of pumps for a wide range of industrial markets — including chemical, mining, oil & gas, power generation, pulp and paper, and general industry. Its global reputation for innovation and quality spans more than 160 years.

www.gouldspumps.com

Good luck
Pierre

 

[SB1976]

Yes, there is a limit on minimum pump efficiency that is indirectly set for the API 610 pumps. As per API 610, the minimum motor rating shall be 4 kW. Hence, if the pump efficiency drops to a value leading to lowering of pump rated power and subsequently lowering motor rating less than 4 kW, that pump would not be accepted.

 

[LittleInch]

Yes, there is a limit on minimum pump efficiency that is indirectly set for the API 610 pumps. As per API 610, the minimum motor rating shall be 4 kW. Hence, if the pump efficiency drops to a value leading to lowering of pump rated power and subsequently lowering motor rating less than 4 kW, that pump would not be accepted.

Well that may lead to an oversized motor but has nothing to do with pump efficiency?

 

[Artisi]

Yes, there is a limit on minimum pump efficiency that is indirectly set for the API 610 pumps. As per API 610, the minimum motor rating shall be 4 kW. Hence, if the pump efficiency drops to a value leading to lowering of pump rated power and subsequently lowering motor rating less than 4 kW, that pump would not be accepted.

Nothing to do with the pump efficiency.

 

[georgeverghese]

For volatile HC condensate, vendor quotes on NPSHr may often require considerable interrogation and can generally be assumed to be suspect.

 

[balasub]

Hi All, Thanks for the response.