Liqui-Cel membrane contactors uses ASME code-rated reverse osmosis (RO) vessels for contactor housings. Devices are rated to 300 psi and utilize combined NPT and Victaulic connections on the shellside for a stacked system design to reduce footprint and weight. Both the 8-in.-by-40-in. and 8-in.-by-80-in. devices use cartridges of polypropylene hollow fiber inside of the RO vessel.