Suction check valves for liquid ring pumps

What it does inside the pump

The check valve on the suction stops the pump from pushing seal liquid backwards into the process line when it stops. A liquid ring pump that shuts down is full of liquid sitting above the suction port, and without a working check valve that liquid drains into whatever the pump was evacuating.

How it fails, and what you see first

Check valves stick open from scale or from solids carried over, and they stick shut from corrosion of the hinge pin. Stuck open is the dangerous one — the failure is invisible while the pump runs and only shows up as a flooded vessel or a flooded line after a shutdown, sometimes months later. Any plant that has ever found seal water in the process after a trip should treat the check valve as a scheduled replacement, not a run-to-failure part.

What to send us so the part is right

Model and serial of the pump, valve size and connection standard (DIN/ANSI/JIS), and the type — swing, wafer or lift. State the process gas, because a valve with an elastomer seat that is fine on air will not last on solvent vapour.

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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