The TSURUMI KRS67.5 is a heavy-duty submersible dewatering pump from Tsurumi's KRS series (officially classed as a general construction pump). It has a 150 mm (6-inch) discharge and a 7.5 kW 4-pole three-phase motor. 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 tunnels, reservoirs and flood situations, handling stormwater, groundwater, wash water and sand-carrying water with solids up to 20 mm.
Selection note: the KRS67.5 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 KRD47.5, KRD611 or KRS-200 slurry pumps, which have a high-chrome impeller and an agitator. If you need the same 150 mm discharge with more head and flow, look at the 11 kW KRS611.
Key features
- Top-discharge, side-flow design: the motor stays cooled even when exposed to air, and the slim pump body fits confined spaces. Keep at least 175 mm of water for continuous running and do not run it dry for long periods.
- Double inside mechanical seals: silicon carbide faces top and bottom (SiC + SiC), running in an isolated oil chamber, plus a lip seal that acts as a dust seal against abrasive particles.
- Tsurumi's original Oil Lifter: forces oil to the mechanical seals and keeps the seal faces lubricated and cooled even when the oil level drops to about one third of normal.
- Built-in circle thermal protector (CTP): cuts the motor circuit directly on excessive heat or overcurrent.
- Anti-wicking cable entry: stops water creeping along the cable by capillary action if the sheath is damaged or the cable end is submerged, with a strain-relief cable clip.
- Low-speed 4-pole motor: continuous-duty dry-type induction motor, IP68, insulation class F, paired with a cast-iron body for long service life.
- 20 mm solids passage: the same as the other 150 mm model, the KRS611.
Applications
- Construction and civil engineering: excavation and foundation dewatering, temporary site drainage
- Tunnels, bridges and dams: seepage and standing water removal
- Reservoirs and dry docks: reservoir and dock drainage
- Storms and flooding: stormwater and emergency flood drainage, provisional sewage drainage
Performance
Tsurumi does not publish numeric maximum head and capacity figures for the KRS67.5. Read from Tsurumi's official 50 Hz performance curve (synchronous speed 1,500 min⁻¹), the maximum head is approximately 19 m, which is the head at near-zero flow, and the curve ends at approximately 2.85 m³/min (about 2,850 L/min) at around 2 m head. The two do not occur together: actual flow falls as total head (static head plus hose friction loss) rises. These are approximate curve readings for preliminary selection only; select the pump from the official performance curve using your site's total head. For more head or flow, consider the KRS611 or the 200 mm KRS811.
Technical specifications
TSURUMI KRS67.5 technical specifications (50 Hz)
| Item | Specification |
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| General |
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| Model | KRS67.5 (North American model KRS2-A6) |
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| Series | KRS (general construction pump, heavy-duty submersible dewatering) |
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| Discharge bore | 150 mm (6 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) | Approx. 19 m (read from official curve) |
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| Max. capacity (curve end point) | Approx. 2.85 m³/min (about 2,850 L/min, read from official curve) |
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| Max. solids size | 20 mm |
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| Electrical |
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| Motor output | 7.5 kW |
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| Motor | Continuous-duty dry-type induction motor, 4-pole, IP68, insulation class F |
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| Speed | Synchronous speed 1,500 min⁻¹ (50 Hz) |
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| Power supply | 3-phase 50 Hz (voltage as per nameplate) |
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| Official 50 Hz rated current | 380 V: 15.8 A; 400 V: 15.0 A; 415 V: 15.0 A (match to nameplate voltage) |
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| Starting method | Direct-on-line (DOL); star-delta on special request |
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| Motor protection | Built-in circle thermal protector (CTP) |
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| Cable | 8 m standard, chloroprene rubber sheath, anti-wicking cable entry |
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| Seals and bearings |
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| Shaft seal | Double inside mechanical seals, SiC + SiC faces top and bottom, oil-lubricated, with Oil Lifter |
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| Oil seal | Lip seal (dust seal) |
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| Lubricant | Turbine oil ISO VG32, 2,300 ml |
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| Bearings | Permanently lubricated, deep-groove, double-shielded C3 ball bearings |
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| Materials |
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| Impeller | Semi-open, ductile cast iron |
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| Suction cover, casing, motor frame | Grey cast iron |
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| Shaft | 420 stainless steel |
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| Liquid limits |
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| Liquid | Stormwater, groundwater, wash water, sand-carrying 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) | 141 kg |
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| Dimensions (L × W × H) | 418 × 379 × 866 mm |
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| Min. water level for continuous running | 175 mm |
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Sources: Tsurumi KRS/KRD series catalogue (IB111), Tsurumi KRS67.5 specification sheet (KRS-06) and Tsurumi KRS series data. Voltage, cable size and rated current of the Hong Kong supply version are as per the nameplate and confirmation from the Hong Kong agent.
KRS series comparison: 100–200 mm
Tsurumi KRS series model comparison (50 Hz)
| Model | Discharge | Power | Max. head | Max. capacity | Max. solids |
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| KRS45.5 | 100 mm | 5.5 kW | approx. 20 m | approx. 2,000 L/min | 12 mm |
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| KRS67.5 (this product) | 150 mm | 7.5 kW | approx. 19 m | approx. 2,850 L/min | 20 mm |
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| KRS611 | 150 mm | 11 kW | approx. 22 m | approx. 3,650 L/min | 20 mm |
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| KRS811 | 200 mm | 11 kW | 17.5 m | 5,500 L/min | 30 mm |
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Note: maximum head and capacity for the KRS45.5, KRS67.5 and KRS611 are approximate values read from Tsurumi's official 50 Hz performance curves.
Optional accessories
- Male threaded coupling (Tsurumi optional accessory, in place of the standard hose coupling).
- Float switch: on a three-phase pump it must switch a control-panel contactor, never the motor directly.
- Motor overload protector or control panel, set to the nameplate rated current.
- A high-temperature liquid version (60–80 °C) is a special factory build, not an add-on accessory.
Safety and installation
- Lift the pump by its handle with a chain or shackle rated for at least 141 kg. Never lift it by the cable or the hose.
- Electrical connection must be made by a registered electrical worker in line with the Hong Kong wiring regulations, with earth-leakage protection. Set the overload relay to the nameplate rated current.
- 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 mud or sand.
- Tsurumi does not list a seawater-resistant kit for the KRS67.5, so the standard model is not suitable for seawater or brackish water. Do not pump liquids outside pH 5–9, oily or chemical liquids, flammable liquids, or liquids above 40 °C.
Wear parts and routine checks
- Main wear parts: impeller, suction cover, mechanical seals and lip seal. With long running in sandy water, the impeller and suction cover gradually wear and flow drops.
- Regularly check the oil in the oil chamber (turbine oil ISO VG32, 2,300 ml). If the oil is cloudy or contains water, have the shaft seals inspected promptly.
