4" submersible pump without motor, type: SP-40-21-M4-2" hydraulics (inox)

Submersible pump STAIRS SP-40-21-M4 for groundwater

The hydraulic part of the STAIRS SP-40-21-M4 submersible pump with a 4" diameter in NEMA standard offers a performance of maximum 180 l/min at a head of 122 meters.

AISI 304 stainless steel construction

The foundation of this pump's reliability is its robust construction made of AISI 304 stainless steel. All key components - the pump housing, discharge and suction ports, cable protector, impeller hubs, impeller, and pump shaft - are made of the same material, ensuring uniform corrosion resistance and long-term durability.

The shaft bushing made of a carbon/graphite/PTFE blend guarantees minimal friction while maintaining high wear resistance. The NBR sleeve bearing ensures operation at a medium temperature of up to 30°C.

Operating parameters and operational safety

The pump can handle water containing a maximum of 50 g/m³ of sand, which significantly expands its range of applications. The integrated check valve located in the discharge connection effectively prevents the medium from flowing back after the pump stops, eliminating the risk of water hammer.

Acid-resistant steel suction baskets provide additional protection against sand and other contaminants entering the pump. The design also includes protective mechanisms during transport and startup - a special thrust ring functions as a thrust bearing, limiting the axial movement of the pump shaft.

Industrial and municipal applications

The model is used in drinking water supply, agricultural irrigation and livestock watering, as well as municipal and industrial water supply systems. It is also used in pressure boosting installations, groundwater drawdown, and fountain supply.

The NEMA mounting standard ensures compatibility with a wide range of electric motors available on the market.