PSH - Impeller Retaining Nut for Giant Pump (Plastic Impeller, Models 17–21) - 3211033

PSH – Impeller Retaining Nut for Giant Pump (Plastic Impeller, Models 17–21)

This is the genuine PSH retaining nut that secures the plastic impeller onto the motor shaft in PSH Giant series pool pumps (sizes 17 to 21). It is a critical fastener in the pump’s wet end: without a correctly torqued impeller nut the impeller can loosen, causing vibration, loss of flow, or pump damage. Replacing a worn or lost nut with an OEM part ensures the impeller stays properly locked during operation.

Compatibility

This nut is designed exclusively for PSH Giant pump models 17 through 21 equipped with a plastic impeller. It corresponds to position 57 in the official PSH Giant exploded-view parts diagram. Always verify your pump model and impeller type (plastic, not cast iron) before ordering, as impeller hardware is highly model-specific.

Why Genuine Matters

The PSH Giant’s plastic impeller operates at high rotational speeds inside a precision logarithmic volute — a design covered by European and international patents. A genuine PSH nut is engineered to the exact thread pitch, torque tolerance, and chemical resistance required for continuous immersion in chlorinated, salt, or sea water. Off-brand substitutes risk stripping the impeller hub or failing prematurely under load.

Installation

Fitting this nut requires the pump to be fully de-energised, isolated, and the wet end disassembled to expose the impeller. Cross-reference position 57 on the official PSH Giant exploded-view drawing to confirm correct placement. Professional installation by a qualified pool technician is recommended to ensure proper torque and to avoid damage to the plastic impeller hub.