An accelerated life testing (ALT) system for the pressurization of corrosive media, such as seawater, at high pressures and at elevated temperatures (up to about 70° C.) for extended periods of time. The interior of a pressure vessel is coated in an inert ceramic/epoxy coating that provides adequate corrosion protection from the corrosive media. A fabric reinforced nitrile diaphragm separates the corrosive media from hydraulic actuating media, such as oil. The hydraulic actuating media is pressurized, which deforms the diaphragm into the corrosive media, thereby increasing the pressure. The diaphragm and supplementary flouroelastomer seals isolate the corrosive media from pressure generating, monitoring, and safety equipment. The temperature of the entire vessel and contents is maintained by complete immersion in a heated, filtered water bath. The system is particularly useful for ALT experiments on components intended for sea floor and long term deep ocean environment operations at about 6000 psi (41.4 MPa).