@ Blacksheep
After initial manufacture, or again after completing major repairs to a fuselage structure, it is the practice to carry out an overblow check. The fuselage is pressurised to at least 150% of the rated Maximum Differential Pressure.
At what kind of A/C are you working???
Here a Quote of the Page i have linked above:
A KC-135 Aircraft was being pressurized at ground level. The outflow valves which are used to regulate the pressure of the aircraft were capped off during a 5 year overhaul and never opened back up. The post-investigation revealed: that a civilian depot technician who, "had always done it that way," was using a homemade gauge, and no procedure.
Ohhh, this technician ist absolutly
Ingo