Contractor Dewatering Pump Kit | Tsurumi LB480

Contractor dewatering pump kit for excavations, site water and flood response

The pump contractors ask for by name, supplied with the hose to actually use it.

This FPS Engineered™ kit pairs the Tsurumi LB480 with 20m of 50mm layflat hose and a stainless-steel clip. The pump takes its own hose tail, so it connects straight out of the box. Choose 110 V for site power through a transformer, or 230 V for building mains.

We have been UK distributors of Tsurumi since 2012, and the LB480 is the model that comes back for more. It is not the cheapest 2 inch dewatering pump we could put in a kit. It is the one that is still working after a winter of being loaded wet into a van, run by whoever was on site that day, and asked to clear footings again the next morning.

Part of our wider Tsurumi, site drainage and 110 V pump ranges.

At a glance

• Around 190 litres per minute: Through the 20 m of layflat supplied, at a typical 2m lift. Roughly 11,400 litres an hour.
• 6mm free passage: Passes the grit, sand and light debris that comes with site water.
• Dual discharge option: 50mm - set horizontally or vertically to prevent hose kinks
• Anti-wicking cable: A Tsurumi standard. Stops water tracking along the conductors into the motor if the cable end ever gets wet.
• 20m of layflat that stores: Rolls flat into a fraction of the space reinforced hose takes, which matters in a van.

What's included

• 1 × Tsurumi LB480 submersible dewatering pump, with hose tail fitted
• 1 × 20m length of 50 mm layflat hose
• 1 × 40 to 60mm stainless-steel hose clip

Choose 230 V for buildings and general-purpose mains, or 110 V for construction sites running through a transformer. Same pump, same hose, same fittings.

How the kit connects

The LB480 has a 2 inch top discharge with its own hose tail, so there is nothing to source and nothing to adapt. Slide the layflat over the tail and tighten the clip. That is the whole assembly.

The discharge can be set to run either vertically or horizontally. In a narrow sump or a deep footing, vertical keeps the hose rising straight out of the chamber with nothing pressing against the walls. In a shallow puddle, a crawl space or under a floor where there is no headroom, horizontal lets the hose run away flat instead of standing up and folding over on itself. Being able to switch it means one pump suits both, rather than you working around whichever orientation it happened to come in.

Expected performance

Estimated flow through the supplied 20m of 50mm layflat with the hose discharging freely. Uphill lift is measured from the water surface to the point where the hose discharges.

Estimated using the published LB480 curve and Hazen-Williams friction for 50 mm bore. At 167 litres per minute a 3 m × 2 m excavation with a metre of water in it, around 6,000 litres, clears in roughly 36 minutes. Friction across the full 20 m run is under 1.2 m of head, so almost all the pump's capability goes into lift rather than being lost in the hose. Work out a specific run with our pump performance calculator.

Technical specification

Why contractors keep buying Tsurumi

Tsurumi have been making pumps in Japan since 1924, and the dewatering range is what the name is built on. Two details explain why the LB480 turns up on so many sites.

The anti-wicking cable. Water finds its way along the inside of a cable, between the conductors, and into the motor. It is one of the commonest ways a site pump dies, and it usually happens because someone left a cable end lying in water. Tsurumi seal against it as standard across the range.

The motor protector. Site pumps get run dry, run against a kinked hose and run in water that is thicker than it should be. The built-in protector cuts the motor before damage rather than after.

110 V or 230 V?

110 V for construction sites, where power comes through a transformer. Site rules generally require it, and a 230 V pump is no use where there are only 110 V outlets.

230 V for buildings, plant rooms, commercial premises and domestic properties on normal mains.

If you work across both, most fleets standardise on 110 V and carry a transformer. Both versions are the same pump with the same performance.

What can I use it for?

• Dewatering excavations, footings and trenches
• Clearing surface water from site compounds, hard standings and access roads
• Flood response in commercial units, basements and plant rooms
• Emptying tanks, chambers, lift pits and manholes
• Groundworks, civils and utilities work where water has to be moved daily
• Hire fleet stock, where the same kit needs to cover several kinds of job

Water quality limits

Frequently asked questions

Why is there no choice of hose length?

Because at 50 mm bore it would not change anything. Going from 10m to 20m of 50mm layflat costs around 3 percent of the flow, which is smaller than the margin of error on the estimate. Rather than ask you to pick between two options that perform the same, we supply the longer one, since running short stops a job and running long does not. Hose can be cut to length to suit your needs. 

Do I need to buy a hose tail?

No. The LB480 comes with its own 2 inch hose tail fitted, so the layflat goes straight on with the supplied clip. Nothing else to source.

Which voltage should I choose?

110 V for construction sites running through a transformer, which is what site rules generally require. 230 V for buildings, plant rooms and domestic mains. The pump performs identically either way.

How is it different from the Trade & Hire Flood kit?

Different jobs. The SPK530 kit clears indoor floods, with reinforced hose for steps and doorways and a pump that takes water down to 1 mm. This kit is for excavations and site water: bigger bore, more flow through the hose, and a pump built for daily site abuse. If you need both, most fleets carry both.

Can I add more hose?

Yes, and at 50 mm it costs very little. Another 20 m would take roughly another 3 percent off. You need a 50 mm joiner and a second clip. Get the water somewhere safe as directly as you can, and avoid tight bends, which cost far more than length does.

Will it pump silty or muddy water?

It passes solids to 6 mm and handles the grit and sand that comes with most site water. Where silt has settled and needs stirring back into suspension, a pump with an agitator is the right tool, because a standard dewatering pump will simply pump clear water off the top and leave the silt behind.

Why Tsurumi rather than a cheaper 2 inch pump?

Longevity and serviceability. The anti-wicking cable entry protects against one of the commonest causes of site pump failure, the motor protector cuts in before damage rather than after, and a Tsurumi is worth repairing rather than replacing. Across a fleet that changes the cost of ownership considerably.