what size pulley ????

[pierre]

i have a gast 3040 pump w/a 7" pulley and i need 1325rpms and i have a 2hp 3450rpm motor what size pulley do i need for the motor ? any and all help would greatly be appreciated !!!!!
thanks pierre

[500592]

What is the pump supposed to spin at.

[twitch]

you need to slow the speed down from the motor so you need a smaller pulley on the motor Its 3040 is 88 percent of 3450 so you pulley circumfrance need to be 88 percent smaller then the seven inch one which comes out to 6.16 so I would say a 6 inch pulley would be close enough. I am pretty sure this is correct if not Im sure someone on here will correct me. :)

[pierre]

the pump stats say 1325rpm needed

[WMF]

You need a 2.68" pulley on the motor so realistically a 2.5" or 2.75" is what you will be able to find.

The farmer formula to use is = drive pulley divided by driven pulley multiplied by motor speed.

2.5 divided by 7 = .357 x 3450 = pump speed of 1232

2.75 divided by 7 = .393 x 3450 = pump speed of 1356

[pierre]

thanks for the info

[twitch]

I thought the pump was 3040 rpm.

you need to slow the speed down from the motor so you need a smaller pulley on the motor Its 3040 is 88 percent of 3450 so you pulley circumfrance need to be 88 percent smaller then the seven inch one which comes out to 6.16 so I would say a 6 inch pulley would be close enough. I am pretty sure this is correct if not Im sure someone on here will correct me. :)

[wiam]

I thought the pump was 3040 rpm.

That is the Gast model #.