Pentair - UltraFlow Plus impeller screws and gasket kit - R39009900

Pentair UltraFlow Plus impeller screws and gasket kit

This is the genuine OEM hardware kit for the Pentair UltraFlow Plus pump, supplying the impeller fastening screws together with the associated sealing gasket. Both components work together to secure the impeller to the motor shaft and maintain a leak-free interface at the impeller face, ensuring the pump delivers its rated flow and pressure.

What this screws and gasket kit does in the UltraFlow Plus

The impeller screws lock the impeller onto the shaft against the rotational forces generated during operation; without them properly torqued, the impeller can work loose and cause bearing damage or total flow loss. The gasket seals the joint between the impeller and the pump body, preventing internal recirculation of water that would rob the pump of efficiency and cause cavitation noise.

Which UltraFlow Plus models it fits

This kit is listed under the Pentair UltraFlow Plus family. Confirm your exact pump variant against the part number R39009900 before ordering — the UltraFlow Plus range spans several motor sizes and the hardware specification can differ between variants.

Señales de que hay que cambiarlo

Replace the screws and gasket whenever you remove the impeller for any reason — the gasket takes a compression set and will not re-seal reliably if reused. If you notice a reduction in flow rate, unusual vibration, or water weeping from the impeller cavity, a compromised gasket or a loose or corroded impeller screw is a primary suspect. Stainless fasteners can still seize in a chlorinated environment over time, making them irretrievable without damage.

Cómo instalarlo

Isolate power and depressurise the pump before starting. Remove the pump lid, basket, and diffuser to expose the impeller. Unscrew the existing impeller screw — note that UltraFlow impeller screws typically use a left-hand thread; turn clockwise to remove. Fit the new gasket dry or with a thin film of silicone grease, then thread the new screw anti-clockwise to engage, torquing to Pentair’s specified value. Reassemble in reverse order and check for leaks on first restart.

Why genuine Pentair matters

Aftermarket impeller screws in the wrong thread pitch or grade will strip or shear under pump torque; an incorrect gasket material will swell, collapse, or extrude, causing the leak you were trying to cure. Genuine Pentair hardware is manufactured to the exact dimensional and material tolerances of the UltraFlow Plus, making it the only safe choice for a pressurised pump assembly.