I once (when I was much younger and much more foolish) made a device for pressure gunking engines by getting an old garden sprayer, drilling a hole in the side (can't remember what size) and screwing in a male PCL quick coupler so I could connect it to my compressor. I ran it at 80 psi and it worked fine, when I first pressurised it I did so with a long airline at a distance.
Usually there is a x2 factor of safety so a 30 psi sprayer should withstand 45 PSI.
To be clear - I'm not recommending this - just pointing out that I once did it and got away with it.... a compressed air vessel with say 7 litres volume can make a right old mess even at just 40 psi.
(This:
https://www.ebay.co.uk/itm/324109800...kAAOSw~yFiUEu-)