How a Rotary Jet Pump Works

What it does: The rotor carries liquid with the shaft and creates the motion needed at the pick-up tube mouth. It is one of the two main working parts.

What wears: Inspect its internal working surfaces for wear or damage. Loss of balance in the rotating assembly can cause abnormal vibration.

When to check: Inspect internally if flow, pressure or power changes while the system requirement stays the same. Check operating causes before replacing parts; refer a loss of balance for factory repair.

What it does: Its fixed mouth receives liquid from the fast-moving outer region of the rotor. The internal passage leads to the stationary outlet.

What wears: Damage can occur at the mouth or in the passage. Hard particles affect wear; a coated tube can help, while the base material addresses chemical resistance.

When to check: Inspect the tube when pressure falls or wear is visible. First check for gas and excessive flow, which can also lower pressure; replace a damaged tube.

What it does: The seal closes the rotor-to-inlet connection and sees suction pressure. The fixed outlet passage carries the high discharge pressure without a moving seal.

What wears: The seal or its O-rings can fail. Check seal faces for scratches, cracks and impact damage before assembly.

When to check: Inspect these parts if leakage appears and replace the failed item. Single or double cartridge seals and flushing support are selected for the liquid, temperature and inlet pressure.

What it does: Bearings support the rotor drive shaft outside the liquid space. Series use either grease or oil-bath lubrication.

What wears: Overload can damage bearings, and low oil level can overheat oil-bath bearings. Grease units have a different lubrication procedure.

When to check: Investigate an unusually hot bearing housing and check its lubrication type first. Replace damaged bearings; bearings removed during dismantling are kept for examination and are not reused.

What it does: The shaft transmits motor rotation to the rotor. Motor-to-pump alignment is checked during installation and maintenance.

What wears: Inspect the shaft and other rotating parts for damage during dismantling. Defective components need replacement before reassembly.

When to check: Review shaft alignment when retaining an existing motor or base. Non-primary replacement parts are made from customer drawings or old-part measurements.