Got my unit to hold pressure! Woot! Took me only 3 high velocity PVC launches to succeed.
It goes Tomato Sauce > 2/12 in to 3 in intake coupler > 3 in to 3 in coupler > 3in PVC end cap > Tire Valves > Pressure Gauge / Bike Pump
I shall try it out in the morning.
Wish me luck!