I see it as an electric clutch on the pump, (like this: https://www.northerntool.com/shop/tools/product_200329776_200329776?cm_mmc=Google-pla&utm_source=Google_PLA&utm_medium=Hydraulics%20%3E%20Hydraulic%20Pumps&utm_campaign=Northern%20Tool%20and%20Equipment&utm_content=1081&gclid=Cj0KCQjwt5zsBRD8ARIsAJfI4BjPCzotZ_ogGTmfZefmuCOOvqoSPNjG9-39nqhywLnYAAik-z9cz5kaAoK0EALw_wcB)
Then no valve between the pump and motor, just hoses and a reservoir. The motor on the hoist runs all the time the clutch is engaged like a PTO would and the hoist is operated normally with the built in valve.
I expect that the speed of the hoist would be regulated by the pulley size and the gpm/pressure relation between the pump and the motor. Of course the pressure/gpm thing would have to be matched to the hoist needs. (PSI x GPM)/1714 = HP)
Weight of load at the center x lift at center gives foot pounds of work to dump. Divide by 33,000 x minutes to complete lift gives HP to lift. Slower lift equals less HP needed.
With a pto, as long as the parts are strong enough the lift gets done. With this setup, It would be good to know what is going on so as to not run too slow or blow something. The pressure in the 'pto' would not matter as long as it is within the ratings of the pump, hose, and motor. I would want the HP rating of the clutch, pump and motor to be able to carry the lift.
I suspect suitable parts might be available used.
If I was doing this for parades, I would likely go with something electric.
If I was going to use this a lot for real work, I think I would go with hydraulics.
I am not a hydraulic guy, I am an engineering technician and test water pumps for a living.
