Materials of the molten salt pump

    The temperature is the starting point for selecting the materials of construction used for the pump. Operating temperature ranges for molten salt start just above their melting point, about 238C, and can run as high as 1200C. The salt chemistry must also be considered, because it is absolutely necessary to understand the temperature at which the molten salt will decompose. Many salts will form hazardous gases and may become more aggressively corrosive at the liquid/atmospheric line of the pump or attack the welds. Because temperature weakens the strength of all materials, the correct materials and designs are reviewed together. The materials used can often compensate for inherently weaker designs being dictated by space limitations or the type of pump used. The reverse is also true, when the design will compensate for weaknesses in the materials due to high temperatures. Understanding this relationship is crucial to selecting the right pump for a given application. The length of the pump and the operating temperature of the molten salt greatly affect the basic design and material selection of the pump. Selecting a material that falls into the marginal range, or even at the extreme high end of the temperature range, can be very dangerous.