understanding pump specs

[4running]

I have been in the middle of upgrading my electric landa from 1.5hp to 6hp. I have decided to change my General pump (for the 3rd time, thisjust keeps getting more and more complicated) out for a larger unit with a higher GPM rating and higher Psi.

My question is, When a horsepower number is given for a particular pump is that the max or the min? Or is it just a suggested Hp to use?

Also if I use too large of a pump, does it just perform at a percentage of its rating? For example will a pump for a 10hp engine produce half of its rated output if driven by a 5hp motor? Or will it be so underpowerd that it produces very little pressure due to having such a high internal rotational mass.

Can I buy a pump for a 9hp motor, then drive it with my 6hp for a reduced rating......maybe a similair performance number that a pump that is actaully rated at 6hp?

Thanks in advance guys!

I am still shopping for a good belt drive pump to suit my needs, but will be a more educated consumer with the correct info.

[Russ Johnson]

The specs on the pump are the maximum recommended operating parameters, and the Hp rating is the required input to attain those specs. Pumps can be slowed to achieve less gpm, and nozzles can be sized to get the pressure that your motor is capable of achieving at that gpm. The formula to figure required Hp is as follows...GPM*PSI/1450=Hp.

[Christopher]

Great info, Thanks Russ.

[4running]

THATS WHAT I NEEDED! Thanks Russ.
I have found a good deal on a HyPro pump, but cant seem to find any info on wether or not guys have been happy with them.

[Russ Johnson]

Hypro makes a good pump...very prevalent in the car wash industry.