Abstract: An apparatus of provided for simulating corrosion activity of a high temperature liquid stream. The apparatus includes a canister in which is positioned a plug, occupying part of the internal volume of the canister. A stream of high temperature liquid enters the canister through an inlet, flows around the plug, and exits the canister through an outlet. The volume and configuration of the plug may be varied to simulate corrosion activity under various flow regimes. Probes may be placed in the liquid stream to detect corrosion activity and temperature. Several canisters may be arranged in series, and corrosion activity may be simulated in each canister simultaneously to determine effects of various parameters such as liquid impingement, velocity, and temperature on corrosion activity.