Who would be interested in one way valves that you could install on your vacuum motors so that you could turn them on one at a time without loosing air pressure through motors that are not on and possibly ruin some motors by turning them on while they are spinning backwards from passing air.
The valves would be about a 6" diameter chamber that you could slip over the housing of the vacuum motor, ot attach to a flat surface. The valve air passage would have a 2" inside diameter.
What would you pay for such a valve?