EN24 cylinder, inside diameter 50 mm, outside diameter 95 mm, wall thickness 22.5 mm.
To be pressurised to 50,000 psi - that's the figure in the relevant literature, and it seems about right - its going to be a hot isostatic press. Effective actual wall thickness is about 17 mm. Not much margin here.
The cylinder is divided into a top and a bottom, and the high pressure area is 50 mm dia, so about 170,000 lb force, 80 tons, needed to keep the top in place.
Now to calculate the needed bolts (which hold together two collars holding the top and bottom parts). Allowing a 3x measure of safety, that's 240 tons yield strength, or 2.4 NM.
For grade 8.8, that's 8 x 24mm bolts - for grade 12.9, it's 8 x 20mm bolts.
Or have I slipped a decimal point, or messed up in the decimal/imperial conversions?
Ta,
-- Peter F