Rated condition in Rotary pump - API-676

[rashaa]

Dear All
i have question on revised API-676 std datasheet.
As you know ,new std api-676 changed liquid properties section.
There are "Min",Normal" & "rated" condition.(see attached picture)
Min and normal condition is obvious.my question is about "rated" condition.
which condition shall be considered as rated condition. please help me.
why "Rated" condition reflected only in API-676 std? we cant see this condition for liquid characteristic in API-610 , 675 , 674 and etc,

thanks

 

[DubMac]

Rated capacity will be the capacity that the pump is guaranteed to perform at, at the Rated pressure. The other points, normal and minimum are NOT essential to the terms of the contract.

 

[Artisi]

As DubMac has advised, the rated performance is usually the guarantee point for hydraulic performance test conditions; unless of course the owner / consultant specify another point as the guarantee point.

For interest, it is not feasible or logical to specify more than 1 point for guarantee - although some consultants in their unfounded wisdom, might well ask for more than 1 point.
But as a pump manufacturer with any sense would say NO to such a demand.

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.)

 

[rashaa]

Dear sirs
Thank you for your reply.
i know that rated point is guarantee point in purchasing any equipment.but this point usually (in API-610,674,675 ,...)related to capacity,differential head.
but in API-676 we can see rated point in liquid specification table.(unlike other standards). this requirement was added in new API-676 std. what is the reason?why only for API-676 ?

 

[rashaa]

nobody could answer?