hi mate, i use a cfr perfect heat pro-500 & i clean carpets at 500psi & upholstery at 250- to 300psi. puts the mockers on what prochem says! carpets & upholstery dry very quickly. regards char
CFR is a different system than normal HWE, you cant compare safe PSI levels between the two.
I wouldn’t use my truck mount at 450 psi on most carpets, BIG chance of damage !
Just because you have a powerful water pump doesn’t mean that you should use it at that PSI.
My car will do 155mph, but I don’t always travel at that speed

Its a tool to be used in a professional manner, to be adjusted to suit each different job.
Very dangerous in the hands of a newbie

Chris