Not sure what you are asking............. but to carry out a ground pressurization check on a 737 classic.... All doors and hatches shut.
Run an engine..... ( as apu rarely has enough air avail to get to max diff ) bleed air on , at least one pack running.
select Man ( AC or DC ) on press. control panel............toggle climb/descend switch to descend (closing the outflow valve )monitoring the cabin VSI and diff press ............easy ! listen to the creeks and groans from the fuselage as it pressurizes......often the VSI suddenly jumps as various seals get blown into place and the fuselage drains close..........
take it slowly so as not to hurt your ears/ sinuses
