The thermoplastic all-welded heat exchangers are designed for heating or cooling in highly corrosive applications. The product line includes immersion, shell-and-tube, tube-plate, gas-liquid, and flexible heat exchangers. The materials of construction include: PVDF (polyvinylidene), Polyethylene, and Polypropylene. These exchangers are ideally-suited for a variety of heating or cooling applications, including heating of pickling acid solutions, electroplating, anodizing, removing heat from chemical dilution reactions, and for acid recovery systems. The heating/cooling media can include saturated steam or hot water up to 35psig at 281 degrees F and chilled water or water/glycol solutions.