According to Pentek tech support, and from my findings, cartridge filter housings are generally designed for 100PSI operation (7bar); however, the pressure drop across the filter media is another thing, and far more important to keep in mind. Pleated cellulose filters are designed to handle 20 PSI (1.4Bar) across the membrane; whereas bag filters are designed for 15 PSI (1bar) across the membrane. Other types of filter media are most probably in these ranges.