When your setting a submersible pump at 200' or better on a traditional pump system your going to get a second check valve below the well seal or pitless adapter(easy access) to take the thump out when pump shuts off. The first check valve got installed on top of submersible pump(never trust the one that comes with pump by itself(seeping back in the future). The whole goal is keeping the submersible from being pulled till it's dead many many years down the road.

Remember that they are spring loaded and one will wear out quicker than using two.

With no flow sleeve and using muilptle check valves in the well these submersible pumps have lasted longer then any other pump system on the market like my own system.

Don't design your system for early failure by using only one check valve inside the pump and leaving water hammer in your system.