Description
Submersible sewage pump is extensively used in industrial, mining and architectural operations, being made of hard alloy and reliably well-sealed and equiped with overheat/overload protection devise, it is also featured by its long durability and safety for use.
Specification
- Size: 50-600mm
- Capacity: 10-6000m3/h
- Head: 5-62m
- Speed: 750-3550r/min
- Temperature Range: ≤80°C
- Sealing arrangement: Mechanical seal
- Electric Motor: 50Hz/60Hz, 110V/220V/380V/440V/460V/660V/1000V
- Materials: Cast iron, SS304, SS316L, Duplex SS, High chrome, Hyperchrome etc
Applications
- Wastewater drainage in factories, construction sites and commercial facilities
- Drainage system in municipal sewage treatment plants
- Drainage station in residential quarters
- Methane pools and field irrigation in countryside
Feature
- Advanced Non-Clogging Impeller: Equipped with a specially designed single or dual-channel impeller, it allows large solids and long fibers to pass through smoothly without causing blockages.
- Heavy-Duty Construction: Built with high-quality cast iron or stainless steel, ensuring excellent wear resistance, corrosion resistance, and a long operational lifespan.
- Dual Mechanical Seals: Features a premium tandem mechanical seal system operating in an oil chamber, providing reliable protection against water leakage into the motor.
- Smart Built-in Protection: Includes automatic thermal overload and leakage sensors to protect the motor from overheating or damage in harsh working conditions.
- Energy-Efficient Design: Optimized hydraulic models ensure high efficiency, low energy consumption, and stable performance across various flow rates.
Packing Declaration
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- All of submersible sewage pump are packed by the standards plywood box complied with the exportation requirement;
- We can also customizing submersible sewage pump package to pack submersible sewage pump according to customer’s request;
WTU Submersible Sewage Pump Technical Data:
| Discharge (MM) | Pump Model | Capacity (m³/h) | Head (m) | Power (kw) | Voltage (V) | Speed (r/min) | Pipe discharg (inch) |
|---|---|---|---|---|---|---|---|
| 25 | 25WTU5-20-0.75 | 5 | 20 | 0.75 | 380 | 2900 | 1 |
| 32 | 32WTU6-18-0.75 | 6 | 18 | 0.75 | 380 | 2900 | 1.2 |
| 40 | 40WTU7-15-0.75 | 7 | 15 | 0.75 | 380 | 2900 | 1.5 |
| 50 | 50WTU10-10-0.75 | 10 | 10 | 0.75 | 380 | 2900 | 2 |
| 65 | 65WTU15-7-0.75 | 15 | 7 | 0.75 | 380 | 2900 | 2.5 |
| 25 | 25WTU5-22-1.1 | 5 | 22 | 1.1 | 380 | 2900 | 1 |
| 32 | 32WTU6-20-1.1 | 6 | 20 | 1.1 | 380 | 2900 | 1.2 |
| 40 | 40WTU7-18-1.1 | 7 | 18 | 1.1 | 380 | 2900 | 1.5 |
| 50 | 50WTU10-12-1.1 | 10 | 12 | 1.1 | 380 | 2900 | 2 |
| 65 | 65WTU15-9-1.1 | 15 | 9 | 1.1 | 380 | 2900 | 2.5 |
| 50 | 50WTU10-16-1.5 | 10 | 16 | 1.5 | 380 | 2900 | 2 |
| 65 | 65WTU20-10-1.5 | 20 | 10 | 1.5 | 380 | 2900 | 2.5 |
| 80 | 80WTU40-7-1.5 | 40 | 7 | 1.5 | 380 | 2900 | 3 |
| 100 | 100WTU50-5-1.5 | 50 | 5 | 1.5 | 380 | 2900 | 4 |
| 50 | 50WTU9-22-2.2 | 9 | 22 | 2.2 | 380 | 2900 | 2 |
| 65 | 65WTU20-15-2.2 | 20 | 15 | 2.2 | 380 | 2900 | 2.5 |
| 80 | 80WTU40-10-2.2 | 40 | 10 | 2.2 | 380 | 2900 | 3 |
| 100 | 100WTU50-7-2.2 | 50 | 7 | 2.2 | 380 | 2900 | 4 |
| 50 | 50WTU15-25-3 | 15 | 25 | 3 | 380 | 2900 | 2 |
| 65 | 65WTU25-18-3 | 25 | 18 | 3 | 380 | 2900 | 2.5 |
| 80 | 85WTU45-12-3 | 45 | 12 | 3 | 380 | 2900 | 3 |
| 100 | 100WTU60-9-3 | 60 | 9 | 3 | 380 | 2900 | 4 |
| 50 | 50WTU15-30-4 | 15 | 30 | 4 | 380 | 2900 | 2 |
| 65 | 65WTU25-25-4 | 25 | 25 | 4 | 380 | 2900 | 2.5 |
| 80 | 80WTU40-16-4 | 40 | 16 | 4 | 380 | 2900 | 3 |
| 100 | 100WTU60-12-4 | 60 | 12 | 4 | 380 | 2900 | 4 |
| 50 | 50WTU15-40-5.5 | 15 | 40 | 5.5 | 380 | 2900 | 2 |
| 65 | 65WTU25-30-5.5 | 25 | 30 | 5.5 | 380 | 2900 | 2.5 |
| 80 | 80WTU40-22-5.5 | 40 | 22 | 5.5 | 380 | 2900 | 3 |
| 100 | 100WTU60-18-5.5 | 60 | 18 | 5.5 | 380 | 2900 | 4 |
| 150 | 150WTU100-7-5.5 | 100 | 7 | 5.5 | 380 | 2900 | 6 |
| 50 | 50WTU20-45-7.5 | 20 | 45 | 7.5 | 380 | 2900 | 2 |
| 65 | 65WTU30-35-7.5 | 30 | 35 | 7.5 | 380 | 2900 | 2.5 |
| 80 | 80WTU40-28-7.5 | 40 | 28 | 7.5 | 380 | 2900 | 3 |
| 100 | 100WTU65-22-7.5 | 65 | 22 | 7.5 | 380 | 2900 | 4 |
| 150 | 150WTU100-12-7.5 | 100 | 12 | 7.5 | 380 | 2900 | 6 |
| 50 | 50WTU20-55-11 | 20 | 55 | 11 | 380 | 2900 | 2 |
| 65 | 65WTU30-40-11 | 30 | 40 | 11 | 380 | 2900 | 2.5 |
| 80 | 80WTU60-30-11 | 60 | 30 | 11 | 380 | 2900 | 3 |
| 100 | 100WTU80-25-11 | 80 | 25 | 11 | 380 | 2900 | 4 |
| 150 | 150WTU100-20-11 | 100 | 20 | 11 | 380 | 2900 | 6 |
| 150 | 150WTU120-15-11 | 120 | 15 | 11 | 380 | 2900 | 6 |
| 200 | 200WTU180-11-11 | 180 | 11 | 11 | 380 | 2900 | 8 |
| 50 | 50WTU20-70-15 | 20 | 70 | 15 | 380 | 2900 | 2 |
| 65 | 65WTU30-60-15 | 30 | 60 | 15 | 380 | 2900 | 2.5 |
| 80 | 80WTU60-40-15 | 60 | 40 | 15 | 380 | 2900 | 3 |
| 100 | 100WTU80-35-15 | 80 | 35 | 15 | 380 | 2900 | 4 |
| 150 | 150WTU100-30-15 | 100 | 30 | 15 | 380 | 2900 | 6 |
| 150 | 150WTU120-25-15 | 120 | 25 | 15 | 380 | 2900 | 6 |
| 200 | 200WTU180-15-15 | 180 | 15 | 15 | 380 | 2900 | 8 |
| 50 | 50WTU20-80-18.5 | 20 | 80 | 18.5 | 380 | 2900 | 2 |
| 65 | 65WTU30-68-18.5 | 30 | 68 | 18.5 | 380 | 2900 | 2.5 |
| 80 | 80WTU60-45-18.5 | 60 | 45 | 18.5 | 380 | 2900 | 3 |
| 100 | 100WTU80-40-18.5 | 80 | 40 | 18.5 | 380 | 2900 | 4 |
| 150 | 150WTU100-36-18.5 | 100 | 36 | 18.5 | 380 | 2900 | 6 |
| 200 | 200WTU180-18-18.5 | 180 | 18 | 18.5 | 380 | 2900 | 8 |
| 50 | 50WTU20-90-22 | 20 | 90 | 22 | 380 | 2900 | 2 |
| 65 | 65WTU30-75-22 | 30 | 75 | 22 | 380 | 2900 | 2.5 |
| 80 | 80WTU60-50-22 | 60 | 50 | 22 | 380 | 2900 | 3 |
| 100 | 100WTU80-45-22 | 80 | 45 | 22 | 380 | 2900 | 4 |
| 150 | 150WTU100-40-22 | 100 | 40 | 22 | 380 | 2900 | 6 |
| 200 | 200WTU200-20-22 | 200 | 20 | 22 | 380 | 2900 | 8 |
| 80 | 80WTU80-13-5.5 | 80 | 13 | 5.5 | 380 | 1450 | 3 |
| 100 | 100WTU110-10-5.5 | 110 | 10 | 5.5 | 380 | 1450 | 4 |
| 150 | 150WTU150-7-5.5 | 150 | 7 | 5.5 | 380 | 1450 | 6 |
| 80 | 80WTU80-20-7.5 | 80 | 20 | 7.5 | 380 | 1450 | 3 |
| 100 | 100WTU100-15-7.5 | 100 | 15 | 7.5 | 380 | 1450 | 4 |
| 150 | 150WTU145-9-7.5 | 145 | 9 | 7.5 | 380 | 1450 | 6 |
| 200 | 200WTU250-6-7.5 | 250 | 6 | 7.5 | 380 | 1450 | 8 |
| 100 | 100WTU100-25-11 | 100 | 25 | 11 | 380 | 1450 | 4 |
| 150 | 150WTU180-11-11 | 180 | 11 | 11 | 380 | 1450 | 6 |
| 200 | 200WTU300-7-11 | 300 | 7 | 11 | 380 | 1450 | 8 |
| 250 | 250WTU400-5-11 | 400 | 5 | 11 | 380 | 1450 | 10 |
| 100 | 100WTU100-30-15 | 100 | 30 | 15 | 380 | 1450 | 4 |
| 150 | 150WTU200-15-15 | 200 | 15 | 15 | 380 | 1450 | 6 |
| 200 | 200WTU250-11-15 | 250 | 11 | 15 | 380 | 1450 | 8 |
| 250 | 250WTU500-5-15 | 500 | 5 | 15 | 380 | 1450 | 10 |
| 100 | 100WTU100-35-18.5 | 100 | 35 | 18.5 | 380 | 1450 | 4 |
| 150 | 150WTU180-20-18.5 | 180 | 20 | 18.5 | 380 | 1450 | 6 |
| 200 | 200WTU250-15-18.5 | 250 | 15 | 18.5 | 380 | 1450 | 8 |
| 200 | 200WTU350-10-18.5 | 350 | 10 | 18.5 | 380 | 1450 | 8 |
| 250 | 250WTU500-7-18.5 | 500 | 7 | 18.5 | 380 | 1450 | 10 |
| 300 | 300WTU650-5-18.5 | 650 | 5 | 18.5 | 380 | 1450 | 12 |
| 100 | 100WTU100-40-22 | 100 | 40 | 22 | 380 | 1450 | 4 |
| 150 | 150WTU200-22-22 | 200 | 22 | 22 | 380 | 1450 | 6 |
| 200 | 200WTU300-16-22 | 300 | 16 | 22 | 380 | 1450 | 8 |
| 200 | 200WTU400-10-22 | 400 | 10 | 22 | 380 | 1450 | 8 |
| 250 | 250WTU500-9-22 | 500 | 9 | 22 | 380 | 1450 | 10 |
| 300 | 300WTU650-7-22 | 650 | 7 | 22 | 380 | 1450 | 12 |
| 100 | 100WTU120-45-30 | 120 | 45 | 30 | 380 | 1450 | 4 |
| 150 | 150WTU180-30-30 | 180 | 30 | 30 | 380 | 1450 | 6 |
| 200 | 200WTU250-22-30 | 250 | 22 | 30 | 380 | 1450 | 8 |
| 250 | 250WTU500-12-30 | 500 | 12 | 30 | 380 | 1450 | 10 |
| 250 | 250WTU600-9-30 | 600 | 9 | 30 | 380 | 1450 | 10 |
| 300 | 300WTU800-7-30 | 800 | 7 | 30 | 380 | 1450 | 12 |
| 300 | 300WTU1000-6-30 | 1000 | 6 | 30 | 380 | 980 | 12 |
| 350 | 350WTU1500-4-30 | 1500 | 4 | 30 | 380 | 980 | 14 |
| 100 | 100WTU120-50-37 | 120 | 50 | 37 | 380 | 1450 | 4 |
| 150 | 150WTU200-35-37 | 200 | 35 | 37 | 380 | 1450 | 6 |
| 200 | 200WTU300-28-37 | 300 | 28 | 37 | 380 | 1450 | 8 |
| 200 | 200WTU350-25-37 | 350 | 25 | 37 | 380 | 1450 | 8 |
| 250 | 250WTU600-12-37 | 600 | 12 | 37 | 380 | 1450 | 10 |
| 300 | 300WTU800-9-37 | 800 | 9 | 37 | 380 | 1450 | 12 |
| 350 | 350WTU1000-6-37 | 1000 | 6 | 37 | 380 | 1450 | 14 |
| 350 | 350WTU1100-6-37 | 1100 | 6 | 37 | 380 | 980 | 14 |
| 400 | 400WTU1300-5-37 | 1300 | 5 | 37 | 380 | 980 | 16 |
| 100 | 100WTU100-57-45 | 100 | 57 | 45 | 380 | 1450 | 4 |
| 150 | 150WTU200-40-45 | 200 | 40 | 45 | 380 | 1450 | 6 |
| 200 | 200WTU300-32-45 | 300 | 32 | 45 | 380 | 1450 | 8 |
| 200 | 200WTU400-25-45 | 400 | 25 | 45 | 380 | 1450 | 8 |
| 250 | 250WTU600-15-45 | 600 | 15 | 45 | 380 | 1450 | 10 |
| 300 | 300WTU800-12-45 | 800 | 12 | 45 | 380 | 1450 | 12 |
| 350 | 350WTU1200-8-45 | 1200 | 8 | 45 | 380 | 1450 | 14 |
| 350 | 350WTU1300-8-45 | 1300 | 8 | 45 | 380 | 980 | 14 |
| 400 | 400WTU1700-6-45 | 1700 | 6 | 45 | 380 | 980 | 16 |
| 100 | 100WTU100-65-55 | 100 | 65 | 55 | 380 | 1450 | 4 |
| 150 | 150WTU180-50-55 | 180 | 50 | 55 | 380 | 1450 | 6 |
| 200 | 200WTU300-40-55 | 300 | 40 | 55 | 380 | 1450 | 8 |
| 200 | 200WTU400-30-55 | 400 | 30 | 55 | 380 | 1450 | 8 |
| 250 | 250WTU600-20-55 | 600 | 20 | 55 | 380 | 1450 | 10 |
| 300 | 300WTU800-15-55 | 800 | 15 | 55 | 380 | 1450 | 12 |
| 350 | 350WTU1000-10-55 | 1000 | 10 | 55 | 380 | 1450 | 14 |
| 350 | 350WTU1100-10-55 | 1100 | 10 | 55 | 380 | 980 | 14 |
| 400 | 400WTU1300-8-55 | 1300 | 8 | 55 | 380 | 1450 | 16 |
| 400 | 400WTU1500-8-55 | 1500 | 8 | 55 | 380 | 980 | 16 |
| 500 | 500WTU2200-5-55 | 2200 | 5 | 55 | 380 | 740 | 20 |
| 100 | 100WTU120-75-75 | 120 | 75 | 75 | 380 | 1450 | 4 |
| 150 | 150WTU200-60-75 | 200 | 60 | 75 | 380 | 1450 | 6 |
| 200 | 200WTU350-45-75 | 350 | 45 | 75 | 380 | 1450 | 8 |
| 250 | 250WTU600-25-75 | 600 | 25 | 75 | 380 | 1450 | 10 |
| 300 | 300WTU800-20-75 | 800 | 20 | 75 | 380 | 1450 | 12 |
| 350 | 350WTU1000-15-75 | 1000 | 15 | 75 | 380 | 1450 | 14 |
| 350 | 350WTU1500-12-75 | 1500 | 12 | 75 | 380 | 980 | 14 |
| 400 | 400WTU1300-13-75 | 1300 | 13 | 75 | 380 | 1450 | 16 |
| 400 | 400WTU1700-10-75 | 1700 | 10 | 75 | 380 | 980 | 16 |
| 500 | 500WTU2000-8-75 | 2000 | 8 | 75 | 380 | 980 | 20 |
| 500 | 500WTU2700-6-75 | 2700 | 6 | 75 | 380 | 740 | 20 |
| 100 | 100WTU120-85-90 | 120 | 85 | 90 | 380 | 1450 | 4 |
| 150 | 150WTU200-70-90 | 200 | 70 | 90 | 380 | 1450 | 6 |
| 200 | 200WTU300-60-90 | 300 | 60 | 90 | 380 | 1450 | 8 |
| 200 | 200WTU400-50-90 | 400 | 50 | 90 | 380 | 1450 | 8 |
| 250 | 250WTU600-30-90 | 600 | 30 | 90 | 380 | 1450 | 10 |
| 300 | 300WTU800-25-90 | 800 | 25 | 90 | 380 | 1450 | 12 |
| 350 | 350WTU1000-18-90 | 1000 | 18 | 90 | 380 | 1450 | 14 |
| 350 | 350WTU1200-18-90 | 1200 | 18 | 90 | 380 | 980 | 14 |
| 400 | 400WTU1300-16-90 | 1300 | 16 | 90 | 380 | 1450 | 16 |
| 400 | 400WTU1500-15-90 | 1500 | 15 | 90 | 380 | 980 | 16 |
| 500 | 500WTU2000-10-90 | 2000 | 10 | 90 | 380 | 980 | 20 |
| 500 | 500WTU2500-8-90 | 2500 | 8 | 90 | 380 | 740 | 20 |
| 600 | 600WTU3000-6-90 | 3000 | 6 | 90 | 380 | 740 | 24 |
| 100 | 100WTU100-100-110 | 100 | 100 | 110 | 380 | 1450 | 4 |
| 150 | 150WTU180-80-110 | 180 | 80 | 110 | 380 | 1450 | 6 |
| 200 | 200WTU300-65-110 | 300 | 65 | 110 | 380 | 1450 | 8 |
| 250 | 250WTU600-40-110 | 600 | 40 | 110 | 380 | 1450 | 10 |
| 300 | 300WTU1000-25-110 | 1000 | 25 | 110 | 380 | 1450 | 12 |
| 350 | 350WTU1300-20-110 | 1300 | 20 | 110 | 380 | 1450 | 14 |
| 350 | 350WTU1600-16-110 | 1600 | 16 | 110 | 380 | 980 | 14 |
| 400 | 400WTU1500-17-110 | 1500 | 17 | 110 | 380 | 1450 | 16 |
| 400 | 400WTU1800-15-110 | 1800 | 15 | 110 | 380 | 980 | 16 |
| 500 | 500WTU2500-10-110 | 2500 | 10 | 110 | 380 | 980 | 20 |
| 500 | 500WTU3000-8-110 | 3000 | 8 | 110 | 380 | 740 | 20 |
| 600 | 600WTU3200-7-110 | 3200 | 7 | 110 | 380 | 980 | 24 |
| 600 | 600WTU3800-6-110 | 3800 | 6 | 110 | 380 | 740 | 24 |
| 150 | 150WTU200-90-132 | 200 | 90 | 132 | 380 | 1450 | 6 |
| 200 | 200WTU400-75-132 | 400 | 75 | 132 | 380 | 1450 | 8 |
| 250 | 250WTU500-50-132 | 500 | 50 | 132 | 380 | 1450 | 10 |
| 300 | 300WTU800-36-132 | 800 | 36 | 132 | 380 | 1450 | 12 |
| 350 | 350WTU1100-28-132 | 1100 | 28 | 132 | 380 | 1450 | 14 |
| 350 | 350WTU1500-20-132 | 1500 | 20 | 132 | 380 | 980 | 14 |
| 400 | 400WTU1700-16-132 | 1700 | 16 | 132 | 380 | 1450 | 16 |
| 400 | 400WTU2000-15-132 | 2000 | 15 | 132 | 380 | 980 | 16 |
| 500 | 500WTU2800-10-132 | 2800 | 10 | 132 | 380 | 980 | 20 |
| 500 | 500WTU3100-10-132 | 3100 | 10 | 132 | 380 | 740 | 20 |
| 600 | 600WTU3700-8-132 | 3700 | 8 | 132 | 380 | 980 | 24 |
| 600 | 600WTU4000-8-132 | 4000 | 8 | 132 | 380 | 740 | 24 |
WTU Submersible Sewage Pump Structure:
- Bearing – SKF or NTN bearings which with a reasonable configuration, it can extend the duration of the pump.
- Cooling – The buit-in cooling system can make pump normally work whether the motor is on or under the liquid surface.
- Motor – Using F class insulation, Max. working temperatures can up to 155 ℃, Protective grade is IP68 with the effective seal.
- Using Burgmann mechanical seal from Germany, two seals are in series with each other and individual work.
- Oil chamber – Oil can lubricate and cool the mechanical seal and preventing liquid penetrating into the motor.
- Impeller – With the optimized design, the impeller wil not be blocked up when to transport liquid with its optimum flow and rate and the maximum efficiency.
- Pump casing – Using the know-how of CAD/CAM to make it at max. efficiency and min wearability.
- Shaft – The pump is coaxial with the motor and the sealing device on the end of the shaft prevents against contacting with the medium to protect it from corrosion.
- Monitor system – Inside of the stator there are three inlaid series heat-control switches, which are in the state of “N.O.” at the normal temperature and opened when the temperature on the stator gets to 125℃ .
- Float switch – The float switch will give a warning signal(the indicator lights), when leakage occurs on the mechanical seal on the motor side, the liquid goes into the switch room and reaches a certain height, to stop the pump. Serviceman should check the mechanical seal and replace it if necessary.
WTU Submersible Sewage Pump Dimension and Installation Drawing:
FAQ:
Q: What is the difference between a standard WTU Submersible sewage pump and the ASWTU submersible cutting pump?
A: The main difference lies in the impeller design and solid-handling capability:
- Standard WTU: Usually equipped with a closed or semi-open channel impeller, ideal for transferring wastewater containing general suspended solids, sludge, and gray water without clogging.
- ASWTU (Cutting/Shredding Type): Specifically fitted with a high-hardness cutting mechanism or shredding impeller. It is designed to chop, tear, and shred long fibers, plastics, textiles, and organic debris into tiny pieces before they enter the pump casing, completely preventing clogging in tough environments.
Q: Can the WTU submersible sewage pump run continuously when it is not fully submerged?
A: Generally, no, standard submersible pumps rely on the surrounding liquid to dissipate heat from the motor. Running a standard WTU pump completely dry or exposed for long periods can cause the motor to overheat and burn out.
💡 Note: If your application requires low-level pumping, look for models featuring an optional external cooling jacket or built-in thermal protection switches.
Q: What materials are used for WTU pumps to handle corrosive or abrasive wastewater?
A: Material selection depends entirely on the nature of the fluid being pumped:
- Standard Industrial/Municipal Wastewater: High-grade Cast Iron (HT200/HT250) or Ductile Iron offers excellent durability and cost-effectiveness.
- Corrosive / Chemical Effluent: Stainless Steel (SS304, SS316, or Duplex Stainless Steel) is utilized to resist chemical corrosion.
- Highly Abrasive Slurry/Sandy Water: High-chrome alloy components or specialized hardened coatings can be applied to extend the service life of the impeller and casing.
Q: What safety protections are built into the WTU sewage pumps?
A: To ensure maximum operational reliability and reduce maintenance downtime, advanced WTU series pumps can be equipped with:
- Thermal Protectors (Overheating): Built-in sensors in the motor windings that automatically shut down the pump if the temperature exceeds safe limits.
- Water Leakage Probe (Moisture Sensor): Positioned in the oil chamber or motor housing to detect any mechanical seal failure before water reaches the motor.
- Dual Mechanical Seals: Usually structured in tandem (Silicon Carbide to Silicon Carbide) to provide a heavy-duty barrier against fluid ingress.
Q: What is the Auto-Coupling System (GAK), and why should I use it?
A: The Auto-Coupling Installation System is a guide-rail mechanism that connects the pump to the discharge piping without manual bolting at the bottom of the sump.
Why use it? It allows for extremely easy maintenance. If the pump needs inspection, you simply lift it via a chain along the guide rails. It automatically disconnects at the bottom and re-connects perfectly when lowered back down—meaning maintenance teams never need to enter the hazardous sewage pit.