The ball valve 1 in size SS316 as 150# rating. On the valve body 5000psi rating is embossed.Are the two pressure equivalent?
Class 150 is rated for 285 psi at 100F in most materials. 
Without straining too hard, you can find an excerpt from ANSI (Now ASME) B16.5 or B16.34 in the technical section of most pipe-valve-fittings catalogs.  Or maybe your company actually has a copy of the standard in the Engineering library.  Both standards have charts of rated pressures of various ferrous materials at a range of tempreatures.
As pointed out in an earlier post: A 5000 psi ball valve >may< have really hard seats that require more than class 150 pressures to seal tightly.  But at least the seats won't extrude at 5000 psi.

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