What is the casing called through which fuel enters after leaving the impeller?

The casing through which fuel enters after leaving the impeller is referred to as the volute. The volute is specifically designed to convert the high-velocity energy of the fuel exiting the impeller into pressure energy. It achieves this by gradually expanding in cross-sectional area, which allows the fluid to slow down and increases its pressure as it moves through the volute.

This design is critical in ensuring that the fuel is directed appropriately into the next stage of the handling or processing system, whether it be into a pipeline, tank, or another equipment component. The volute's function is vital for optimizing the performance of the fuel handling system and for maintaining efficiency.

The other terms, such as chamber, compressor, and separator, refer to different components or functions in fuel systems but do not specifically describe the function of directing fuel flow after it exits the impeller in the way that the volute does.