Unit HB 50/50

The upgraded semi-submersible unit NV-M is a unit with a vertical axial supply of the medium to the open-type impeller and with a spiral discharge of the medium from the casing through a branch pipe and through a pressure pipe to the support plate. The pump (supply, impeller, casing, branch pipe) is separated from the chassis by an oil chamber with a double mechanical seal. The pump chassis - the lower shaft and the upper shafts, connected through half couplings and sprockets, are driven by an electric motor through a coupling. The coupling consists of an upper half coupling, a half coupling and sprockets. The support of the rotating lower shaft is a 3309E-2Z SKF rolling bearing. The supports of the rotating upper shafts are 6307-2Z SKF rolling bearings. The bearings do not require additional lubrication throughout their service life. The direction of rotation of the pump shaft is clockwise when looking at the pump from the engine side. The shafts are located in sealed hangers - the lower hanger and the upper hangers - protective pipes with flange connections. Changing the immersion depth of the pump is achieved by changing the length and number of upper hangers and upper shafts. The tightness of the hangers is ensured by a double mechanical seal, which consists of two single mechanical seals of the same design. The arrangement of single mechanical seals is of the tandem type, i.e. sequential. The lower mechanical seal prevents leakage of the pumped medium from the pump side, located in the cover of the oil chamber. The friction pair of the lower mechanical seal is cooled by the pumped medium, which enters through the hole in the cover of the oil chamber from the tank and is discharged into the pump casing. The upper mechanical seal on the atmospheric side is located in the separating oil chamber and is cooled by synthetic motor oil 0W40. The tightness of the suspensions is controlled by a float level sensor - contactless level switch PDU2.1.10-EX. Failure of one of the end seals leads to leaks in the lower suspension. When the leak level rises to 125±3 mm from the suspension base, PDU2.1.10-EX is triggered, a signal is sent to the control panel.