Pentair Diffuser O-Ring Parker No. 2-238 | WhisperFlo & IntelliFlo Pumps | 355227Z

Description

The Pentair Diffuser O-Ring (355227Z) is the OEM replacement Parker No. 2-238 O-ring for the diffuser on WhisperFlo and IntelliFlo variable speed pump models.

⚠️ IMPORTANT: DATE-OF-MANUFACTURE FITMENT QUALIFIER
Fitment for IntelliPro VS+SVRS and IntelliFlo VS+SVRS models is confirmed for units manufactured after June 2016. Fitment for IntelliFlo i1 and i2 models is confirmed for units manufactured after April 2016. If your pump was manufactured before these dates, verify the part number stamped on your original O-ring before ordering.

This O-ring seals the diffuser inside the pump’s wet end, preventing recirculation of water around the impeller and maintaining hydraulic efficiency. A deteriorated or missing diffuser O-ring allows water to bypass the impeller, reducing flow and pressure output. Replacing this O-ring restores the tight seal between the diffuser and pump body during routine wet-end service or impeller replacement.

Specifications

Fits Into

Compatibility is based on Pentair parts documentation and available OEM records. This is not an exhaustive list. For certainty, verify the part number in your equipment’s manual or on the original part itself before ordering.

Pro Tip

When you have the pump’s wet end disassembled for impeller or diffuser service, replace the lid O-ring at the same time — it’s inexpensive insurance against a callback. The Parker 2-238 designation is molded or stamped on the original O-ring; confirm this designation matches before adding to cart. Apply a thin coat of Pentair-approved silicone-based lubricant to the O-ring before reassembly to seat it evenly and extend service life.