Every hydraulic cylinder is tested in the factory:
Test pressure = 1.5 x max. operating pressure.
Standards applied:
DIN ISO 6020-1 (mounting dimensions)
ISO 8132 (accessories)
With the respective type of fixation, the operating pressure indicated in the parts list can be exploited statically and dynamically without restrictions. However, the safety respectively required in your system and the stress caused by dynamic movement must be taken into account.
If other sealing systems such as Servofloat® are used, the mounting length increases accordingly and may deviate from the standard dimension.