Sludge Motor Pumps

Sludge motor pump — what it is and when to choose one

A sludge motor pump is a petrol-driven centrifugal pump with large open impeller and inspection cover enabling pump cleaning without disassembly. It pumps the most contaminated media — sludge, slurry, thick deposits, liquids with large solid particles up to 27 mm diameter. That's three times more than semi-slurry motor pump (8-9 mm) and 5 times more than clean water motor pump (up to 5 mm). Impeller design requires trading some hydraulic performance for medium handling — sludge pump delivers proportionally lower head (26-30 m vs 32 m in clean water pumps of same power class).

Main applications: emptying septic tanks and settling tanks municipal and industrial, pumping sludge from biogas plants, work on livestock farms (slurry from pigs, cattle, poultry), emptying flooded excavation pits archaeological or post-flooding with large amounts of silt, pumping from mining settling tanks, municipal works (rainwater with sediment).

Models table — Koshin sludge motor pumps with Honda engines

Lightest: KTH50X (47 kg, 2", 700 l/min) — for smaller work at home septic tanks and farms up to 50 cattle. Highest flow: KTH100X (4", 1650 l/min = 99 m³/h) — for large biogas plants, industrial farms and municipal work. Highest head: KTH50X (30 m) — when you need to pump sludge to a higher level.

Practical flow in m³/h — what you actually pump

Catalog flow is the value at zero head and short suction hose. In real working conditions (4 m head + 7 m suction hose, dense medium with 2-3x higher viscosity than water) flow drops by 40-60%. Real working values:

Frequently asked questions — sludge motor pumps

Which sludge motor pump for emptying a home septic tank?

For typical home septic tank 8-12 m³ Koshin KTH50X is enough (2", 700 l/min, Honda GX160 engine, 47 kg) — empties 10 m³ septic tank in about 30 minutes of real work. Handles solids up to 20 mm — sufficient for septic tanks of 4-6 person family. For larger septic tanks (industrial, hotel >20 m³) or municipal — KTH80X (3", 1340 l/min) or KTH100X (4", 1650 l/min). Remember about permits for waste transport and discharge approval at designated location.

Is a sludge motor pump suitable for pumping slurry on a farm?

Yes — sludge motor pumps are standard choice for livestock farms (pigs, cattle, poultry). Slurry has 2-3x higher density than water and contains organic particles up to 25 mm — requires sludge pump with open impeller. KTH80X (3", 1340 l/min, handles up to 27 mm) will handle 50 m³ slurry tank in ~1 hour (real time 30-40 m³/h). For very large industrial farms (tank 100+ m³) → KTH100X (4"). After slurry work rinse pump with clean water for 10-15 minutes — organic acids damage seals. Change engine oil more often (every 50 engine hours instead of 100) due to ammonia fumes.

What is the price of a sludge motor pump?

Koshin sludge motor pump prices with Honda GX engines depend on diameter: KTH50X (2", 700 l/min, Honda GX160) — from 4,887 PLN net. KTH80X (3", 1340 l/min, Honda GX240) — 6,533 PLN net. KTH100X (4", 1650 l/min, Honda GX340) — 9,481 PLN net. Sludge motor pumps are 50-100% more expensive than semi-slurry due to larger impeller construction, heavy housing and higher-power Honda GX engines. Additionally for 4" (KTH100X) thicker discharge and suction hoses are required (660 PLN for suction hose 4"/8 m, 610 PLN for discharge hose 4"/20 m) and Storz Al couplings 4" (72 PLN each).

What is the inspection cover and why is it important?

Inspection cover is a removable plate in pump body enabling quick access to impeller without pump disassembly. When pumping sludge, impeller clogging with a large particle (e.g. leaf, stone 30+ mm, plastic piece) happens 1-2 times a year with intensive use. Without inspection cover you have to disassemble the whole pump (hours of work + risk of seal damage). With cover — unscrew 4 bolts, remove foreign body, assemble in 5 minutes. All Koshin KTH models (KTH50X, KTH80X, KTH100X) have inspection cover.

Can I pump sludge from a farm pool or pond?

Yes, but watch out for small stones and shells — in natural reservoirs particles >27 mm often lie on the bottom (pebbles, shells, branches). Sludge pump handles up to 27 mm — larger particles will clog the impeller. Solution: lift suction hose 15-20 cm above bottom to avoid drawing large particles. For water with dense silt and small particles (up to 27 mm) KTH50X (700 l/min) or KTH80X (1340 l/min) will work perfectly. After work rinse pump with clean water for 10 minutes — fine sand will settle in impeller and over time increase seal wear.

How much does a sludge motor pump weigh and can I carry it alone?

Koshin KTH sludge motor pumps weigh from 47 kg (KTH50X) to 78 kg (KTH100X). That's much heavier than semi-slurry pumps (23-31 kg) due to larger impeller, more powerful engine (Honda GX160-GX340) and reinforced frame. KTH50X (47 kg) can be lifted single-handed (man) or by two people (women) — has side handles. KTH80X (59 kg) and KTH100X (78 kg) require two people to carry or transport set with wheels (~530 PLN net). For field work KTH100X (78 kg) is best transported on a trailer or in a delivery van.

What Honda engine does Koshin KTH100X motor pump have?

Koshin KTH100X (largest sludge motor pump in our offer) has Honda GX340 engine — 4-stroke, 337 cm³, Japanese, one of the most durable 11 HP class engines available on the market. Fuel tank 6.1 l, oil pan 1.1 l. Runtime per fill: ~2.5-3 hours at nominal load. Service kit GX340/390 VKER (lower air filter, spark plug, engine oil) — replacement every 100 engine hours (267 PLN net, available in generator accessories). Honda specifies GX340 engine lifespan at 3,000-5,000 engine hours with regular kit replacement.