West Warwick Welding, National Board Certified ion exchange tanks rated at 100 psi @ 100F. Board number 7050. The inlet and outlet are 2 inch pad flange fittings with butterfly valves located in the upper and lower side sheet. There is a 4 inch sight window in the upper side sheet and a 1-1/2 inch drain with a stainless steel ball valve on the bottom. These are portable, skidded tanks in excellent condition.