ROmate reverse osmosis permeate storage vessels reduce costs while maintaining quality. ROmate-40 is a 40 gallon Reverse Osmosis Tank. Structural ROmate-20 Storage Tanks have a polyethylene inner shell and a fiberglass exterior. ROmate-20 Fiberglass Storage Tanks feature 100% Seamless construction, and the ability to discharge in any position. ROmate-40 storage tanks feature a removable air cell which allows for easy service and sanitation or replacement as needed. Pentair ROmate-20 Storage Tanks are pre-charged at 10 PSI.