Research and development, production, processing, and sales of water pumps, complete sets of water supply and drainage equipment, mobile drainage equipment, HVAC equipment, energy-saving and environmental protection equipment, electrical control equipment, water treatment equipment, valves, water tanks and fluid equipment, and new integrated pump stations; Water and electricity installation; Installation of mechanical and electrical equipment; Central air conditioning, cold storage, hot water system, HVAC engineering construction and equipment sales; Sales of building materials, hardware and plumbing equipment; Self operated or agency import and export business of various domestic goods or technologies (excluding those restricted or prohibited by the state). (For projects that require approval by law, business activities can only be carried out after approval by relevant departments