Couplings for liquid ring pump sets

What it does inside the pump

The coupling joins the motor shaft to the pump shaft and, on a flexible type, absorbs the small residual misalignment that no baseplate holds forever. It does not correct misalignment — it tolerates it.

How it fails, and what you see first

Coupling hubs are a semi-wear item: they fail through bore fretting, keyway spread after running loose, and cracking of the jaw or the pin holes. What is usually replaced first, and far more often, is the elastomer element between the hubs. Repeated element failure is a symptom, not a cause — it means the alignment is out or the pump is being started against a flooded casing.

What to send us so the part is right

Model and serial of the pump, plus the motor frame size and shaft diameter, or just the coupling size stamped on the hub. Give both bore diameters and keyway sizes. Tell us the coupling type (jaw/spider, pin-and-bush, or grid) so we quote the matching half.

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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