Percent Head Rise" and "Percent Head Reservation 1

[migueldiazch]

Reviewing some Project BID Tabulation documents for API 610 Pumps I found the term "Percent Head Rise" and "Percent Head Reservation" as a requested specification. For some services the Percent Head Rise was limited to >120 for others the number was <120 and in some service there were no specification. For the term Percent Head Reservation, the specification was limited to >5.

Can somebody explain me what does "Percent Head Rise" and "Percent Head Reservation" mean?

Best regards,
M.D

 

[1gibson]

Former is "head rise to shutoff" and it is a comparison between rated head and shutoff head. It is a simplified description of the curve shape, more head rise is "steep" and less head rise is "flat." Both have advantages and disadvantages, depends on what kind of system and how it will be operated.

Latter is "future head increase" which means the pump selected is capable of this (via change in impeller diameter, type, number, or overspeed) without major modification. It prevents you from having to select a new pump if the system calcs were off and you need additional head once things are installed.

 

[migueldiazch]

Thanks for the info. Very helpfull

M.D