4" submersible pump without motor, ST-55-24-M4-2" hydraulics

Advanced hydraulics for demanding applications

The hydraulic part of the STAIRS ST-55-24-M4-2" submersible pump is a professional solution designed for the toughest groundwater pumping tasks. The 4" diameter model in NEMA standard offers an impressive maximum performance of 250 l/min and a lift height of up to 141 m, making it an ideal choice for deep wells and boreholes.

Top-class construction and materials

The robust construction based on AISI 304 stainless steel guarantees long-term resistance to corrosion and aggressive environments. Key elements such as the pump housing, discharge and suction outlets, cable protector, and impeller hubs are made of this high-grade material, ensuring reliability in all operating conditions.

Impellers made of NORYL are characterized by exceptional resistance to mechanical wear, while polycarbonate diffusers ensure optimal hydraulic characteristics. The AISI 431 stainless steel pump shaft guarantees the transmission of high torque without the risk of deformation.

Innovative technical solutions

The floating impeller system is a key innovation protecting the pump from failures resulting from potential sand intake. Impellers mounted on movable sleeves allow for the pumping of small amounts of sand without damaging the hydraulic components. Upon contact with sand particles, the impeller gently rises, preventing the pump from jamming.

The check valve factory-installed in the discharge outlet eliminates the risk of medium backflow after the pump is turned off. The shaft sleeve made of a carbon/graphite/PTFE composite and the polyoxymethylene plain bearing ensure minimal friction and maximum durability of the drive system.

Operating parameters and compatibility

The device operates in S1 continuous mode and can pump medium at temperatures up to 35°C with a sand content of up to 150 g/m³. The NEMA connection standard allows the hydraulics to be connected to most available submersible motors from various manufacturers, significantly expanding application possibilities.

The pump is designed for installation in wells with a minimum diameter of 4" (102mm), while the diameter of the device itself is 95 mm (98 mm including the cable protector). The maximum number of starts per hour is 40, allowing for intensive operation in systems requiring frequent startup.