The TSURUMI KRD35.5 (formerly KRS2-80) is a heavy-duty submersible slurry pump with an agitator, from Tsurumi's KRD/KRS series. It has an 80 mm (3-inch) discharge and a 5.5 kW 4-pole three-phase motor. A high-chrome cast-iron agitator on the shaft stirs up settled solids so they can be drawn in, and the semi-open impeller and suction plate are also high-chrome cast iron for wear resistance. It is built to pump slurries laden with silt, earth and sand, with solids up to 30 mm.
Selection note: the KRD35.5 is a slurry pump, with an agitator and high-chrome wear parts for settled sediment and sandy slurry. If you only need to drain site water carrying a small amount of sand, a KRS series heavy-duty dewatering pump without an agitator (such as the KRS811) is the better fit. The KRD35.5 is not a sewage pump and is not suitable for wastewater containing fibrous solids.
Key features
- High-chrome agitator: re-suspends settled solids so the slurry flows smoothly into the pump.
- High-chrome wear parts: the semi-open impeller and the suction plate are both high-chrome cast iron. When wear reduces performance, it can be restored by replacing the suction plate.
- Top-discharge, side-flow design: keeps the motor cooled even when it runs exposed to air, and reduces the overall pump diameter for confined spaces. Keep the liquid above the lowest running water level (265 mm).
- Double inside mechanical seals: silicon carbide (SiC) faces in an oil chamber, with Tsurumi's Oil Lifter to keep the faces lubricated and cooled even when the oil drops to about one third of the normal level.
- Dust seal: the oil seal shields the mechanical seals from abrasive particles.
- Built-in circle thermal protector (CTP): cuts the motor circuit directly on overheating or overcurrent.
- Anti-wicking cable entry and cable clip: limit water creeping along the cable into the motor.
- 4-pole dry-type induction motor: continuous-duty rated, insulation class F.
Applications
- Construction sites: pumping sandy water and settled slurry from excavations, shafts and pits
- Pit and tank desilting: removing settled silt, earth and sand
- Civil engineering works such as tunnels, bridges and dams: discharging slurry laden with silt, earth and sand
Liquid limits: 0–40 °C, pH 5–9, up to 20% dry matter. The standard model is not intended for seawater, chemical or corrosive liquids, sewage containing fibrous solids, or flammable liquids.
Performance
The 15.8 m maximum head is the head at near-zero flow, and the 1,670 L/min (about 100 m³/h) maximum capacity is the end point of the performance curve (50 Hz). The two do not occur together: actual flow falls as total head (static head plus hose friction loss) rises, and slurry density also affects real-world output. Select the pump from the performance curve using your site's total head. For more head or flow, consider the KRD47.5 (17.1 m) or KRD611 (22 m).
Technical specifications
TSURUMI KRD35.5 technical specifications (50 Hz)
| Item | Specification |
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| General |
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| Model | KRD35.5 (formerly KRS2-80) |
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| Series | KRD/KRS (slurry pump with agitator) |
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| Discharge bore | 80 mm (3 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) | 15.8 m |
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| Max. capacity (curve end point) | 1,670 L/min (approx. 100 m³/h / 1.67 m³/min) |
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| Max. solids size | 30 mm |
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| Electrical |
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| Motor output | 5.5 kW |
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| Motor | 4-pole dry-type induction motor, continuous-duty rated, insulation class F |
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| 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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| Starting method | Direct-on-line (DOL); star-delta available to order |
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| Motor protection | Built-in circle thermal protector (CTP) |
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| Cable | 8 m (standard), chloroprene rubber sheath |
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| Seals and lubrication |
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| Shaft seal | Double inside mechanical seals, silicon carbide (SiC) faces, oil-lubricated, with Oil Lifter |
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| Oil seal (dust seal) | Nitrile rubber (NBR) |
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| Lubricant | Turbine oil ISO VG32, 1,850 ml |
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| Materials |
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| Impeller | Semi-open, high-chrome cast iron |
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| Agitator | High-chrome cast iron |
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| Suction plate | High-chrome cast iron |
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| Pump casing, suction cover | Grey cast iron |
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| Motor frame | Grey cast iron |
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| Shaft | 420 stainless steel |
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| Liquid limits |
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| Liquid temperature | 0–40 °C |
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| pH | 5–9 |
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| Max. dry matter | 20% |
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| Dimensions and weight |
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| Dry weight (excl. cable) | 107 kg |
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| Dimensions (L × W × H) | 351 × 326 × 838 mm |
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| Lowest running water level | 265 mm |
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Sources: Tsurumi KRS/KRD series catalogue (IB111) and Tsurumi Europe KRD series data (head, capacity, liquid limits and lowest running water level are 50 Hz figures). Voltage and rated current of the Hong Kong supply version are as per the nameplate.
KRD/KRS slurry pump series comparison
Tsurumi KRD/KRS slurry pump model comparison (50 Hz)
| Model | Discharge | Power | Max. head | Max. capacity | Dry weight |
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| KRD35.5 (this product) | 80 mm | 5.5 kW | 15.8 m | 1,670 L/min | 107 kg |
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| KRD47.5 | 100 mm | 7.5 kW | 17.1 m | 2,350 L/min | 154 kg |
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| KRD611 | 150 mm | 11 kW | 22 m | 3,250 L/min | 175 kg |
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| KRS-200 | 200 mm | 18 kW | 31 m | 4,800 L/min | 395 kg |
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All four models pass solids up to 30 mm.
Optional accessories
- Motor-protection starter or control panel: a three-phase pump must be connected through external overload and earth-leakage protection. The pump has no float switch or built-in control panel.
- Hose couplings and BS-threaded couplings in various sizes.
- Booster adapter: connects two KRD35.5 pumps in series for higher head.
- Jetting system: dissolves sediment to support agitator pumps.
- TSS seal-oil leakage sensor (external; requires an additional relay).
- Seawater-resistant kit (galvanic anode plus seawater-resistant special cast-iron impeller), offered as a KRS/KRD series option.
These couplings and accessories are listed by Tsurumi for overseas markets. Please contact us to confirm availability in Hong Kong.
Safety and installation
- The pump weighs 107 kg dry (excluding cable). Lift it by the handle with suitable lifting gear, never by the cable or the hose.
- Wiring, earthing and protective devices must be installed by a registered electrical worker in line with local regulations, with overload and earth-leakage protection. The built-in CTP does not replace external motor protection.
- Check the direction of rotation before first use. If it is wrong, have an electrician swap two phases.
- Keep the liquid above the 265 mm lowest running water level and never run the pump dry.
- The pump is not explosion-proof. Do not use it with flammable or explosive liquids or in explosive atmospheres, and do not pump liquids above 40 °C or outside pH 5–9.
- The standard model is not seawater-resistant; seawater use requires the seawater-resistant kit.
- Always isolate the power before inspection or servicing. The agitator and impeller edges can cause cuts.
- Website information may differ from the actual specification. Refer to the delivery specification sheet before use.
Wear parts and routine checks
- Main wear parts: high-chrome suction plate, impeller, agitator, mechanical seals and oil seal. Long running in abrasive slurry gradually wears the impeller and suction plate, and performance drops.
- Check the oil in the oil chamber regularly (turbine oil ISO VG32, 1,850 ml). Water or slurry in the oil indicates mechanical-seal wear; have the seals inspected promptly.
- When performance drops, inspect the impeller and suction plate; replacing the suction plate restores performance.
