Learn More About Concrete Line Pumps
A concrete line pump is a twin-cylinder, positive-displacement pump that pushes concrete through a fixed pipeline of steel pipe and rubber hose rather than through an articulating boom. The TRUEMAX LP100 is a truck-mounted line pump — the pumping unit on a road-legal Dongfeng or Sinotruk chassis — and the same hydraulic line pump unit is also sold as a towed trailer (stationary) pump. Because output is delivered through a pipeline you lay out yourself, the working reach of a line pump is set by pump pressure, pipe diameter and line geometry, not by a published boom length.
How the pumping unit generates pressure
Two concrete cylinders work in opposition. On the suction stroke one cylinder draws concrete from the hopper; on the delivery stroke the S-valve (S-tube) swings across to that cylinder and the piston forces the charge into the DN 150 outlet while the second cylinder refills. The cylinders are driven by hydraulic cylinders on an open circuit, so concrete pressure equals hydraulic pressure multiplied by the ratio of hydraulic-piston area to concrete-piston area. This is why the two LP100 models differ. The LP100.18.253D uses a Ø230 × 1800 mm concrete cylinder that displaces about 75 litres per stroke, favouring volume; the LP100.23.360D uses a Ø200 × 1800 mm cylinder displacing about 57 litres per stroke, which concentrates the same hydraulic thrust on a smaller piston face and raises concrete pressure to 23 MPa. Both are rated at 100 m³/h theoretical output and run roughly 22–30 strokes per minute depending on bore; the real difference is where each puts its energy — volume per stroke versus pressure per stroke. The delivery cylinders are chrome-plated on the inner wall for a service life over 100,000 m³, and the cutting ring and glass (spectacle) plate at the valve are rigid-alloy consumables checked against pumped volume.
Pressure, distance and reach
Reach is a pressure-loss problem. Concrete in a vertical line needs roughly 1 bar for every 10 m of lift; horizontal runs lose pressure to wall friction, and every bend, reducer and length of hose adds resistance expressed as equivalent metres of straight pipe. A practical planning figure is Equivalent Horizontal Pumping Distance (EHPD): add the horizontal run to about five times the vertical run, then add the equivalent length of each bend. A pump that handles a long horizontal line will manage a much shorter vertical rise once that multiplier is applied, which is why a high pressure line pump is specified for long distance concrete pumping and for high-rise risers, while a higher-output, lower-pressure unit suits flat work. Pipe diameter also counts: a DN 125 line raises pressure loss per metre against DN 150 but suits confined, fine-detail placement, and reducers between diameters add their own resistance. Fix these variables before selecting a model — the headline 100 m³/h and 23 MPa figures are ceilings, not field guarantees.
Concrete that pumps cleanly
The pump tolerates a wide mix window, C15 to C70, but pumpability depends on the mix as much as the machine. Maximum aggregate size should stay within roughly one-third of the smallest pipe diameter for rounded aggregate and about one-quarter for crushed or angular stone; on a DN 125 line that is broadly 40 mm rounded or 30 mm crushed. A slump in the region of 100–180 mm pumps reliably; below that, line pressure climbs and blockage risk rises. Adequate fines and a controlled water-cement ratio keep the mix cohesive so it neither bleeds nor segregates under pressure. For a concrete pump for slab and foundation work the priority is throughput; for long horizontal runs and risers it is a cohesive, well-graded mix that holds pressure without separating. Sending your mix design with the enquiry lets the right cylinder bore and pipeline diameter be matched to the job.
Line pump vs boom pump, and truck-mounted vs trailer
The most common selection question is line pump vs boom pump. A boom pump places concrete directly through a truck-mounted arm and sets up in minutes, so it is faster on open, high-volume pours and for reaching over obstacles. A line pump has no boom; the crew lays pipe and hose to the placement point, which is slower to set up but costs less, fits tight access, and runs concrete farther horizontally. When to use line pump vs boom pump comes down to volume, access and budget: confined city-centre sites, residential slabs and foundations, repairs, grouting and long horizontal runs favour the line pump; large open pours favour the boom. The second question is truck-mounted versus trailer. Both use the identical pumping unit; the truck-mounted line pump — widely called a city pump for its ability to work narrow streets and congested yards — drives itself between jobs on its own chassis, while the trailer (stationary) pump is towed, stays on one site, and does the same pumping work for lower outlay.
Specifying and sourcing
When requesting concrete line pump specifications from a manufacturer or supplier, the figures that determine the model are: required output in m³/h matched to your ready-mix supply rate; maximum pumping distance and height; the number of pipeline bends; concrete grade and maximum aggregate size; and the chassis registration and emission standard required in your market. On the LP100, chassis brand, engine (Deutz or Cummins), power and emission level are all configurable, and the onboard control system logs running hours and fuel use and supports remote diagnostics. As a concrete line pump manufacturer building in-house at Haining, TRUEMAX supplies the pumping unit, configures the pipeline to your layout, and keeps cylinders, S-valves, cutting rings and glass plates in stock for delivery to over 120 countries. Send your site conditions and we will confirm the model, pipeline and wear-part plan.
