7 bar is only 102 psi, and that is no problem for piping itself. It is too much for fixtures, however.Actually the pump I have produce 5 bar on its own add to that the city pressure at night which can reach more than 1.5 bar so the total pressure can reach 7 bar which is too much for the piping system
If you use a pump controlled by a pressure switch, with or without a CSV, the pressure at the fixtures would not rise higher than the pressure switch cut-off pressure. With a CSV, if the pressure rose to 150 or more before the CSV, that would not hurt the pipes or the CSV.
Without a CSV, you need a bigger pressure tank. With no CSV, if the flow from the pump is X liters/minute, then the pressure tank should be 4*X liters or bigger.