Technical Bid Evaluation in Api Pumps

[tonystark14]

Hi guys,

I recently came across a thread which stated the functions of a mechanical engineer in API pump selection. Can anybody help me out in understanding the concept of selection in such pumps? What would happen if the technical factors like flow, NPSH, seals, efficiency, etc. of the pumps provided by all the vendors do not match with the client's criteria? Can the mechanical engineer do any adjustments in the design provided by the vendor?

 

[Artisi]

Seems like a simple fix, if the pump vendors can't meet the client's criteria then it stands to reason the application should be reviewed to suit what is available from the pump manufacturers.
It is fairly easy to write a spec. that is impossible to meet therefore, it stands to reason that the clients engineer should have really spent sometime with the manufacturers data and reviewed what is being designing as compared to what is reasonable available to meet requirements. Also, most major pump manufacturers are usually very willing to give advice / suggestions early in the design stage to ensure they have their name out there, they know there is a project in the offering and they are in a position to bid later for the supply.

It's pretty easy to do, a simple phone call is usually enough, like "Hi, I'm just reviewing an application for a pump /s to achieve X flow at Y head, NPSHa will be A, temp. is B, pumps will be to API spec, do you have something in your pump range so we can review where we are going"

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.)

 

[tonystark14]

Artisi....thanks for the reply....the problem however arises when all the vendors fail to meet the criterias you mentioned above.....As a rotary engineer in EPC, what can we do in such situations?.....can you please advice?

 

[LittleInch]

I agree with Artisi - you can ask for the moon, but you need to have someone to supply it or it remains a dream. Sounds like a re-design to me. The fact that no one can do the things you ask for imply that there is something seriously wrong with the requirments on the data sheet. How about giving us a few examples?? sometimes the difference between spec/data sheet and vendor supply is not so large and you can accept the deviation.

Why not call the vendors and ask then what is feasible and why they can't comply and then maybe you'll be able to explain better to your superiours why you can get what was in the scope.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[Artisi]

tonystark14: - not much you can do, if you must use API pumps you are bound by what is available.
By saying they don't meet the criteria - what don't they meet.
Sounds to me the vendors have offered pumps for your enquiry that come somewhere near to your requirements and they must be happy with their selection from a mechanical and hydraulic standpoint - otherwise why would they stick their necks out. You now need to review the offers / spec. to see what is needed to fit the pumps to the system / system to the pumps.

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.)

 

[LittleInch]

API specs can sometimes be a little bit prescriptive, especially for relatively small, non hazardous fluids where there is no generic "spec", but you take what the vendor gives you and look at it carefully. If whoever wrote the data sheet didn't understand say API 610 carefully, you could easily specify a machine which is outside the requirements of the code.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way