Depends, what kind of repairs are we talking about? If you're just changing out a seal you probably don't need any. If you had to weld a crack in the casing I'd look at radiography/UT testing & hydrotesting, if you installed a new impeller I'd think about a performance test, if you installed a new electric motor you'd might be as simple as bump test to make sure it was wired in right, not to mention alignment checks. If it was some modifications done to the rotor of a high speed or multistage pump, you might be looking at vibration & torsional testing again. There's a lot of different tests to be run, really depends on what you did.