Pumps and Motor Pumps

An engine-driven pump has its own petrol or diesel engine, so it works in the field without mains access — on site, for land drainage or dewatering far from a socket. An electric pump on a 230 V or 400 V supply runs more quietly and without exhaust, most often as a submersible unit for excavations and cellars. Engine-driven pumps reach higher output (over 1,500 l/min with a 3–4 inch port), while electric pumps win on indoor mobility and continuous work without refuelling.

Access to power and the nature of the work decide the choice. With a 230 V or 400 V socket a submersible electric pump is usually more convenient — quiet, fume-free and ideal for dewatering cellars and excavations. In terrain without power the only option is an engine-driven pump, mobile and grid-independent, with output from 500 to over 1,500 l/min. Also account for the water type: slurry needs 25–30 mm solids passage, dirty water 8–10 mm.

A clean-water pump has a closed impeller and narrow channels, so it passes only fine particles up to about 5 mm and serves for transfer or irrigation. A trash pump has an open impeller and larger ports, so it passes grains and suspended solids up to 25–30 mm — suitable for mud, sediment and construction-site water. For intermediate dirty water (particles 8–10 mm) a dirty-water or submersible pump is enough.

Output depends mainly on the port diameter. A 2 inch pump (50 mm) moves roughly 500–700 l/min, a 3 inch model (80 mm) reaches 1,000–1,300 l/min, and a 4 inch unit (100 mm) delivers 1,600 l/min and more, at a head of around 25–30 m for clean water. Real output drops with pumping height and hose length, so these figures are industry ranges — exact data is on each product page.

A high-pressure pump such as the Koshin SERH 50 V delivers high working pressure (up to approx. 7–8 bar) and a head of around 50–70 m instead of high flow. It is used for long-distance irrigation, surface washing and pumping water to upper floors — wherever the reach of the jet matters more than the volume moved. It runs on clean water and, unlike a trash pump, is not designed for suspended solids.

For a flooded cellar or excavation an electric submersible dirty-water pump works best — it is placed directly in the water and runs quietly and fume-free in an enclosed space. Choose a unit with 8–10 mm solids passage, because flood water carries sand and fine debris; in the NORWIT.PL range Wacker Neuson dominates here. When there is no power or a large excavation must be dewatered fast, use a 3 inch engine-driven pump with an output of 1,000–1,300 l/min.

An engine-driven pump needs a reinforced suction hose (which will not collapse under vacuum), a delivery hose, a suction strainer with a foot valve and couplings matching the port — 2 or 3 inches. Without a foot valve the pump loses its prime and stops drawing after a standstill. Hose diameter is critical: too narrow a hose can cut output by tens of percent, so a 3 inch port uses an 80 mm hose. Hoses, couplings, strainers and filters are in pump accessories.

The difference comes down to output and scale of use. A 2 inch port equals 50 mm and moves roughly 500–700 l/min — enough for small excavations, garden irrigation and emptying cellars. A 3 inch port is 80 mm and gives 1,000–1,300 l/min, meaning equipment for site work, larger dewatering and ponds. The 3 inch model is heavier and burns more fuel, but it dewaters faster and, in trash pumps, passes larger particles.

Price depends on the drive type, output, impeller material and brand. Simple submersible electric pumps start from a few hundred zloty, engine-driven clean-water pumps of 2–3 inches usually fall between about 1,500 and several thousand zloty, and professional trash pumps and hydraulic units cost from a few to over ten thousand zloty. The engine also matters — diesel is more expensive than petrol. Current prices are shown on each product page.

The basics are changing the engine oil every roughly 25–50 running hours (the first change after about 20 h of run-in), regular air-filter cleaning and spark-plug checks. After every job with dirty water or slurry, flush the pump body with clean water so deposits do not dry on the impeller. Before a longer standstill drain the pump and fuel system, and in frost remove any remaining water so it does not crack the casing — with these rules a pump lasts several thousand running hours.