The TSURUMI KRS815 is a heavy-duty submersible dewatering pump from Tsurumi's KRS series (officially classed as a general construction pump). It has a 200 mm (8-inch) discharge and a 15 kW 4-pole three-phase motor, and delivers up to 21.5 m of head and up to 6,400 L/min. With a semi-open ductile-iron impeller, a grey cast-iron body and a low-speed motor, it is built for high-volume drainage on construction sites, in tunnel and dam projects and during flood emergencies, and handles site water carrying a small amount of sand and silt (up to 15% dry matter, pH 5–9, solids up to 25 mm).
Selection note: the KRS815 is a dewatering pump, not a slurry pump. It has no agitator and no high-chrome wear parts, so it is not suitable for settled sludge, dense sand slurry, desilting or dredging. For that duty, choose the KRD611 or KRS-200 slurry pumps, which have a high-chrome impeller and an agitator. Among the 200 mm models, the KRS811 passes larger solids (30 mm), and the KRS822 reaches a higher head (34.8 m).
Key features
- Top-discharge, side-flow design: the motor stays cooled even when partly exposed, and the slim body fits confined spaces. Keep at least 275 mm of water for continuous running and do not run it dry for long periods.
- Double inside mechanical seals: silicon carbide (SiC) faces on both the upper and lower seals, running in an isolated oil chamber, with Tsurumi's original Oil Lifter to keep the seal faces lubricated and cooled even when the oil drops to about one-third of its normal level.
- Dust-seal protection: a nitrile rubber lip seal keeps abrasive particles away from the mechanical seal.
- Built-in circle thermal protector (CTP): cuts the motor circuit directly on overheating or overcurrent.
- Anti-wicking cable entry: stops water creeping along the cable cores into the motor if the sheath is damaged or the cable end is submerged; a cable clip provides strain relief.
- Low-speed 4-pole motor: continuous-duty rated, about 1,440–1,470 rpm at 50 Hz, paired with a cast-iron body for long service life.
- Flexible starting: direct-on-line (DOL) as standard, star-delta available to order, and suitable for soft starters and variable-frequency drives (VFD).
Applications
- Construction and civil engineering: excavation and basement dewatering, temporary site drainage
- Tunnels, bridges and dams: removal of seepage and standing water during works
- Flood-control pumping stations: boosting stormwater discharge capacity
- Docks and reservoirs: dock drainage and reservoir drainage
- Storms and flooding: emergency drainage and temporary sewage drainage
Performance
The 21.5 m maximum head is the head at near-zero flow, and the 6,400 L/min (about 384 m³/h) maximum capacity is the end point of the performance curve. The two do not occur together: actual flow falls as total head (static head plus hose friction loss) rises. Select the pump from the 50 Hz performance curve using your site's total head, and avoid continuous running on the dashed section of the curve near shut-off. For a higher head, consider the KRS822 (34.8 m); for more volume at a lower head, consider the KRS1022 (12,000 L/min).
Technical specifications
TSURUMI KRS815 technical specifications (50 Hz)
| Item | Specification |
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| General |
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| Model | KRS815 |
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| Series | KRS (general construction pump, heavy-duty submersible dewatering) |
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| Discharge bore | 200 mm (8 in) |
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| Discharge connection | Hose coupling (standard) |
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| Hydraulic performance |
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| Max. head (at zero flow) | 21.5 m |
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| Max. capacity (curve end point) | 6,400 L/min (384 m³/h / 6.4 m³/min) |
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| Max. solids size | 25 mm |
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| Electrical |
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| Motor output | 15 kW |
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| Motor | 4-pole dry-type induction motor, continuous duty, IP68, insulation class F |
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| Speed | approx. 1,440–1,470 rpm (50 Hz) |
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| Power supply | 3-phase 50 Hz (voltage as per nameplate) |
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| Starting method | Direct-on-line (DOL); star-delta available to order; suitable for soft starters and VFDs |
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| Motor protection | Built-in circle thermal protector (CTP) |
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| Cable | 8 m, chloroprene rubber sheath (Tsurumi standard) |
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| Seals and bearings |
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| Shaft seal | Double inside mechanical seals, silicon carbide (SiC) faces, isolated oil chamber, with Oil Lifter |
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| Oil seal | Nitrile rubber lip seal (dust seal) |
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| Lubricant | Turbine oil ISO VG32, 3,200 ml |
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| Bearings | Double-shielded deep-groove ball bearings (C3) |
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| Materials |
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| Impeller | Semi-open, ductile cast iron (EN-GJS-700-2) |
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| Casing and suction cover | Grey cast iron (EN-GJL-200) |
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| Motor frame | Grey cast iron (EN-GJL-200) |
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| Shaft | 420 stainless steel (X30Cr13) |
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| Liquid limits |
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| Liquid | Stormwater, groundwater, wash water and sand-carrying site water |
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| Liquid temperature | 0–40 °C |
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| pH | 5–9 |
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| Max. dry matter | 15% |
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| Max. submersion depth | 40 m |
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| Dimensions and weight |
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| Dry weight (excl. cable) | 255 kg |
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| Dimensions (L × W × H) | 489 × 460 × 1,069 mm |
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| Min. water level for continuous running | 275 mm |
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Sources: Tsurumi KRS/KRD series catalogue (IB111, 2025 edition), Tsurumi KRS model specification sheets and Tsurumi Europe KRS series data (50 Hz). Earlier specification sheets list the weight as 240 kg. Voltage, cable and rated current of the Hong Kong supply version are as per the nameplate and confirmation from the Hong Kong agent.
KRS series comparison: 200 mm and larger
Tsurumi KRS series model comparison (50 Hz)
| Model | Discharge | Power | Max. head | Max. capacity | Max. solids |
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| KRS811 | 200 mm | 11 kW | 17.5 m | 5,500 L/min | 30 mm |
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| KRS815 (this product) | 200 mm | 15 kW | 21.5 m | 6,400 L/min | 25 mm |
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| KRS822L | 200 mm | 22 kW | 26 m | 5,900 L/min | 25 mm |
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| KRS822 | 200 mm | 22 kW | 34.8 m | 5,300 L/min | 25 mm |
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| KRS1022 | 250 mm | 22 kW | 12.2 m | 12,000 L/min | 25 mm |
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What's in the box
- KRS815 pump with attached cable × 1
- Hose coupling × 1
Optional accessories
- Male threaded coupling (in place of the standard hose coupling).
- Seawater-resistant kit (galvanic anodes with fittings, plus a seawater-resistant special cast-iron impeller), ordered from the factory.
- Float switch. Three-phase pumps must be connected through a control panel; the float switch should switch the panel contactor, never the motor directly.
- Motor overload protector or control panel, set to the nameplate rated current.
A 60 °C high-temperature-liquid version is also available as a special factory build, not as an accessory.
Safety and installation
- The pump weighs about 255 kg dry. Lift it by its handle with a chain or shackle rated for the load. Never lift it by the cable or the hose.
- Electrical connection must be made by a registered electrical worker in line with local regulations, with earth-leakage protection. Set the overload relay to the nameplate rated current. For direct-on-line starting, size the cable, breaker and generator for a 15 kW motor.
- Check rotation before first use: at start-up the pump body should kick anticlockwise when viewed from above. If it turns the wrong way, have an electrician swap two phases. Do not hold the handle while checking.
- After the built-in motor protector trips, the motor restarts automatically once it cools. Always isolate and lock off the power before inspection or servicing.
- Stand the pump on a firm or raised base so it does not sink into silt.
- Do not run continuously below a water level of 275 mm, avoid prolonged dry running, and do not run for long periods on the dashed section of the curve near shut-off.
- The standard model is not seawater-resistant; without the seawater kit it is not recommended for seawater or brackish water. Do not pump liquids outside pH 5–9, flammable, oily or chemical liquids, or liquids above 40 °C.
Wear parts and routine checks
- Main wear parts: impeller, suction cover, mechanical seals and oil seal. With long running in sandy water, the impeller and suction cover gradually wear and flow drops.
- Regularly check the oil condition in the oil chamber (turbine oil ISO VG32, 3,200 ml) and the clearance between the impeller and the suction cover. If the oil is cloudy or contains water, have the shaft seals inspected promptly.
