WATERRO MEMBRANE HOUSING MODEL: 4021-FRP THREAD (300 PSI) WATERRO 4021-FRP THREAD (300 PSI) membrane housing is a glass-fibre-reinforced plastic (FRP) membrane housing for standard 4" × 21" reverse osmosis membranes. It provides high mechanical strength, excellent corrosion resistance and a long service life. The housing is designed to operate at a maximum working pressure of 300 PSI (20.7 Bar) and is equipped with a threaded end connection for secure installation. Technical specification Parameter Value Product FRP RO membrane housing Model 4021-FRP THREAD Housing size 4021 (4" × 21") Compatible membrane Standard 4021 RO membrane Material Glass-fibre-reinforced plastic (FRP) Housing type Threaded Maximum working pressure 300 PSI (20.7 Bar) Connection type Threaded Number of membranes 1 Application Commercial and industrial RO systems Brand WATERRO Key advantages FRP construction Designed for standard 4021 RO membranes 300 PSI maximum working pressure High resistance to corrosion and chemicals Lightweight and durable housing Threaded construction Secure leak-tight seal Suitable for RO, NF and UF systems