It is perfectly possible to print parts to hold pressure. For a project about a year ago we printed 60 mm diameter pressure vessel tops including internal passages and connection fitting threads . We used Spectrum Nylon PA6 LW . We made more than 75 of these parts and hydraulic proof tested them to 6 to 7 BAR or over 100 psi .
But before you go ahead you must make sure that the design is suitably for manufacturing this way and Hydraulic proof test to
At least twice the working pressure. If something goes wrong at these pressure it makes an awfully loud BANG and as fred_dot_u said you don't want the pieces flying around!!!!?