Which is used to stop air leakage into the casing around the pump shaft?

The seals are specifically designed to prevent air and fluid leakage along the pump shaft. They create a barrier that minimizes the space where air can enter the casing around the pump shaft. This is crucial in maintaining the efficiency of the pump operation and ensuring that it operates correctly under the intended conditions.

In pump systems, seals can take various forms, including mechanical seals or elastomeric seals, which are selected based on the application's requirements. By effectively stopping air leakage, seals help maintain prime, prevent contamination from entering the pump, and facilitate smooth operation.

Other components like the packing gland, lantern ring, and shaft sleeves play important roles in pump design and function. For example, the packing gland is used to hold packing material against the shaft for sealing but does not solely stop air leakage. The lantern ring serves as a support for the packing and often incorporates a way to provide lubrication, while shaft sleeves are protective coverings for the shaft itself. However, none of these components are primarily responsible for stopping air leakage as effectively as seals do.