Yes it has a toilet type diaphragm valve, and it raises the pressure to the pump, where one must have a pressure switch to shut it off. I have one with a small tank near the submersible, and one without - they both work ok. But I am using the electric float. This valve is truly a piece of ingenuity. I would guess the shut off is slow, so the tank is likely not needed.
Cement around a steel static tank? Thats called a pipe bomb with no fuse to know when its going off.