Abstract: Systems and methods for preventing diffusers in pumps such as electric submersible pumps from bursting or collapsing in over-pressure and/or under-pressure conditions, where one or more diffusers in the pump includes check valves in the exterior diffuser wall. The check valves remain closed when a pressure differential between the diffuser interior and exterior is within a predetermined range, but open when the pressure differential between the diffuser interior and the interstitial space is outside the predetermined range to relieve overpressure and underpressure conditions. When the pressure differential returns to an acceptable range, the check valves close, preventing recirculation of fluid between the diffusers of the different stages. O-rings or other types of seals may be installed between each stage and the pump housing to provide some isolation of the external pressure on the diffuser of each stage.

Abstract: Systems and methods for preventing diffusers in pumps such as electric submersible pumps from bursting or collapsing in over-pressure and/or under-pressure conditions, where one or more diffusers in the pump includes check valves in the exterior diffuser wall. The check valves remain closed when a pressure differential between the diffuser interior and exterior is within a predetermined range, but open when the pressure differential between the diffuser interior and the interstitial space is outside the predetermined range to relieve overpressure and underpressure conditions. When the pressure differential returns to an acceptable range, the check valves close, preventing recirculation of fluid between the diffusers of the different stages. O-rings or other types of seals may be installed between each stage and the pump housing to provide some isolation of the external pressure on the diffuser of each stage.

Abstract: An electrical submersible pump has a pump assembly joined to a seal section. The pump assembly shaft, which may experience upthrust axial forces, may joined to the seal section shaft by a detachable coupling. The detachable coupling may have splines on its inner diameter that engage splines on the outer diameters of the pump assembly shaft and the seal section shaft. The detachable coupling can be bolted to one of the shafts. Locking members, such as plates, can be inserted through slots on the coupling to engage a recess on one of the shafts. A retaining device, such as a sleeve, can be used to hold the locking members in place.