floodbuster
most professionals agree on from 200 to 500 psi depending on what fabric or kind of carpet is being cleaned
Heat! Most fabrics can take heat up to 220 no problem. But a professional technician will know how much and when

Dry cleaners can't compete! Most professional carpet cleaners(steam cleaners) also have dry cleaning available when dry cleaning is needed, but only when needed. Almost all trade magazines geared toward carpet cleaning look at dry clean only companies as a scam and or joke in the industry. simply because they can't compete.