Max.design pressure rating:300psi,450psi,600psi,1000psi,1200psi Model:4021,4040-1W,4040-2W,4040-3W,4040-4W Accommodates standard make 4"Membrane Element Operating Temp Range:-10°C--49°C Feed / Concentrate port 1"coupling,Permeate port 1/2",3/4"female Operating Temp.Range:-10°C-49°C Operating pH Range:3-11 Cleaning pH Range:2-12(less than 30 minutes) Test pressure 100%QA test with 1.5x design hydraulic pressure ASME:1.1x Design Pressure