Koshin Ponstar PX Submersible Pumps

Where to Use Koshin Ponstar PX Pumps

Construction site dewatering is where the PX earns its keep. Excavations, foundation trenches, lift pits and basements under construction fill with water carrying sand, cement fines and silt, which is exactly what wears out a cast iron impeller. The polyurethane wet end copes with that abrasion, and the 110v models plug straight into a site transformer. Stand the pump on a firm base, such as a paving slab or brick, rather than soft mud, so it draws water rather than ground.

Plant hire fleets, flood response teams and maintenance departments use the PX for the same reason: it is light enough to carry, simple to set up and tolerant of rough handling. In flooded cellars, plant rooms and car park sumps, the automatic models will cycle on and off by themselves. If the pump is likely to be left running after the water has gone, or you need more lift, the Koshin Ponstar PBX and PBX7 add dry-running protection and up to 15 m of head. For fixed sump installations, our guide to choosing the right size sump pump explains how to match flow to the inflow you expect. If you are unsure whether you need a drainage, dirty water or sewage pump, our explainer on what a dirty water pump is sets out the differences.

Two limits are important. The PX passes fine solids only (around 3 mm), so it is not suitable for raw sewage, sludge, stones or fibrous waste; our dirty water pumps range covers heavier solids. It also will not pump a floor dry. Once the water drops below the intake it loses suction, and a residue pump such as the Koshin Ponstar PXL is the better tool for clearing the last few millimetres.

Frequently Asked Questions

What is the difference between the PX 55022 and the PX 55011?

Only the supply voltage. The PX 55022 is the 230v mains version and the PX 55011 is the 110v version for construction sites and other reduced-voltage supplies. Both deliver 260 l/min with a maximum head of 10 m and share the same body, outlet and dimensions. The 110v models draw more current, so allow for this when sharing a site transformer.

Do I need a float switch with the manual PX?

Only if the pump will run unattended. A manual PX runs for as long as it has power, so on an unattended job it will keep running after the water has gone, which wears the mechanical seals. Either choose an automatic model, which has a float switch fitted, or wire the manual pump through one of our float switches or a control panel.

Can the Ponstar PX pump sandy or silty water?

Yes, and this is what it is designed for. The polyurethane impeller and volute plate flex slightly as abrasive particles pass, so they wear far more slowly than cast iron parts on the same water. Keep the pump off the bottom of the excavation where possible, so it is not sitting in settled sediment and drawing in stones larger than it can pass.

What hose fits the PX outlet?

Each pump has a 2-inch BSP female outlet with a hose tail, so it takes standard 2-inch (50 mm) layflat or suction hose. The outlet turns from vertical to horizontal, which stops the hose kinking where it leaves the pump. On long runs, hose friction reduces the flow you will see at the far end; our guide to pump discharge pipe sizing explains how to allow for it.

How high can the PX pump water?

The maximum head is 10 metres, but that is the height at which flow falls to zero. The higher you lift the water and the longer the hose, the lower the flow, so the full 260 l/min is only available with little or no lift. Our guide to pump head and flow rate shows how to read the performance curve on each model page.

Can the PX run continuously?

Yes. The PX is continuously rated, provided the motor stays submerged so the surrounding water keeps it cool. Running it dry or in a few centimetres of water for long periods is what shortens seal life, which is another reason to choose an automatic model for long or unattended jobs.

If you would like help choosing between the PX models, or matching a Koshin pump to a particular site or sump, call the AES Rewinds team on 01252 515169 or email sales@aesrewinds.com. You can also compare the full Koshin range or browse all drainage pumps.