Liquid ring pump impellers

What it does inside the pump

The impeller is the only rotating element inside the pump body. Its blades do not compress gas themselves — they drive the seal liquid outward into a ring against the casing bore, and the gas is trapped in the crescent-shaped cells between the blades and that ring. Because the impeller is mounted eccentric to the bore, each cell grows on the suction side and shrinks on the discharge side, and that changing cell volume is the whole pumping action.

How it fails, and what you see first

Impellers fail from the tip inwards. Cavitation near the discharge port thins and pits the blade tips; in acidic or chloride-bearing seal water the blade roots corrode and the blade edges go ragged. The symptom a plant sees first is not noise — it is that ultimate vacuum has crept up and the pump no longer holds the duty point, while motor current drops slightly because the ring is carrying less liquid. Cast-iron impellers running on cooling-tower water with chlorides are the most common case we re-supply.

What to send us so the part is right

Send the pump model and serial number, plus a nameplate photo. If the pump is already open: blade count, outside diameter, hub bore, keyway width, and overall hub length. State the seal liquid and its temperature — that decides whether you need HT250 gray iron, 304, 316/316L, duplex 2205 or bronze. We check the profile against the original drawing before quoting.

Which models take this part (273)

Grouped by pump family. Model numbers in blue have their own page with the full specification table; the rest are supplied from the same frame — send the model and we confirm against the drawing.

Other parts for the same machine

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