Discharge casing and vertical submersible pump provided with the same

摘要

It is an object of the present invention to provide a vertical submersible pump capable of properly releasing air from an internal space of a pump body when a water level is recovered. A discharge casing 9 is used in the vertical submersible pump. The discharge casing 9 includes a joining thread portion 18b formed in at least a part of an outer surface of the discharge casing 9. The joining thread portion 18b is configured to be threadedly engaged with a female thread portion formed in an inner surface of an outer casing 24. At least one air releasing groove 25 that cuts across a thread of the joining thread portion 18b is formed in the joining thread portion 18b.