Posted by Don in NH [216.107.193.154] on Thursday, August 27, 2015 at 15:09:34 :
In Reply to: Re: PS Pump - "Controlled flow" versus "Pump capa posted by Desoto61 [138.162.0.41] on Thursday, August 27, 2015 at 11:35:59 :
I am swinging back to how your were thinking - the 1.5 is the nominal flow at a certain RPM and the 7.5 is the max. There are some charts for the VTM42 (which is the modern replacement I think) which show flow versus rpm and have curves for the control flow rates.
So my pump at 1.5gpm will increase flow linearly up to about 6500RPM, at which time the flow control kicks in at 7.5gpm.
If this is true, it will be nice as I can fiddle with pulleys as I need more flow.
Below is a link to a big pdf with the flow data for the vtm42.