Which is the best pressure maintaining test method for hydraulic one-way valve?

The plan on the right will definitely not work. If the oil pump is on, the leakage of the hydraulic lock can't be seen at all, and it will overflow to generate heat. If the pump is stopped, the pressure will immediately return to zero, and the oil pump itself will not maintain the pressure.

The one on the left is ok, but it is best to add a small accumulator near the pressure gauge, otherwise the pressure fluctuates greatly and the effect of maintaining pressure by a little oil in the pipe is not obvious. Also consider the exhaust setting when the pipeline is supplied with oil.