Hydro jetting pressures on certain pipes ?

I was wondering what psi is safe to jet 3" and 4" cast iron, pvc and concrete. These three our what i see most commonly here in oklahoma. Also something that bothers me is if i come up against a 90 in a 3 or 4 inch sewer and i have a root ranger on the end will i blow a hole in the 90? Really curious about this and i hope you jetter guys can help me out.:smile:

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