Submersible sewage pumps, specifically designed for conveying sewage containing solid particles, fibers, and suspended solids, directly impact the operational efficiency and safety of drainage, sewage treatment, and emergency flood control systems.To ensure comparability and traceability across design, manufacturing, inspection, and use, the industry has established a relatively complete system of technical specifications, covering performance parameters, structural requirements, material selection, testing methods, and safety guidelines.
Regarding performance parameters, technical specifications typically specify key indicators such as flow rate, head, power, efficiency, and particle size. Flow rate ranges from a few cubic meters per hour to several thousand cubic meters per hour, depending on the application scenario. Head is determined by pipeline resistance and lifting height. For sewage containing solids, specifications stipulate the maximum permissible solid particle size and fiber length, commonly ranging from 20 to 80 mm, with specific values depending on the pump type and application. Efficiency indicators not only reflect hydraulic performance but also relate to energy consumption levels, typically using a minimum percentage as a pass/fail criterion.
The structural design must meet the special requirements for long-term underwater operation. The motor should employ a waterproof sealing structure, and the stator windings must undergo vacuum pressure impregnation. The insulation resistance under normal conditions should meet the minimum limit for the corresponding voltage level. The shaft sealing system is recommended to use a double-end mechanical seal or a mechanical seal with an oil-filled chamber isolation structure, and should be equipped with a leakage alarm or automatic shutdown function. The pump body and impeller materials should be selected according to the corrosiveness of the medium, using cast iron, ductile iron, stainless steel, or special alloys to ensure sufficient strength and corrosion resistance. The overall structure should ensure coordination between the center of gravity and buoyancy, and vibration and noise during operation should be controlled within the specified limits.
Materials and manufacturing processes must comply with relevant national and industry standards. Castings must be free of shrinkage cavities, cracks, and slag inclusions that affect strength; welds must undergo non-destructive testing; rotating parts should be dynamically balanced to reduce mechanical stress during high-speed operation. Exposed metal surfaces should be treated with anti-corrosion measures, such as epoxy resin spraying or galvanizing, to extend service life.
Regarding testing methods, the specifications require type testing and factory testing before delivery. Type testing includes performance curve determination, overload testing, sealing leakage testing, and temperature rise testing to verify the pump's comprehensive performance under specified operating conditions. Factory testing focuses on sealing, rotation direction, insulation resistance, and no-load operation checks to ensure each piece of equipment meets basic safety requirements.
Safety specifications emphasize both electrical and mechanical protection. Electrical equipment should meet waterproofing requirements, generally not lower than IP68; moving mechanical parts should have reliable protection to prevent injury from contact. Overcurrent, overheat, phase loss, and leakage protection devices must be installed during use, and warning signs should be placed in prominent locations.
Following unified equipment technical specifications establishes clear technical benchmarks during the selection, procurement, installation, and acceptance of submersible sewage pumps, reducing operational risks caused by parameter mismatches or inconsistent quality, and providing a solid guarantee for the efficient, safe, and long-term operation of sewage transport systems.
