Pentair Black O-Ring | Sta-Rite Posi-Flo II Cartridge Filters | WC9-3 Drain & Suction Covers Replacing this part restores proper

Replacing this part restores proper hydraulic distribution and full filtration performance

It’s an environmentally safe product that isn’t corrosive

Fitment for IntelliFlo i1 and i2 pumps is confirmed for units manufactured after April 2016

needing only the minimal amount of sanitizer

Each pump requires two (2) of these unions — one on the suction side and one on the discharge side

Pentair Black O-Ring | Sta-Rite Posi-Flo II Cartridge Filters | WC9-3 Drain & Suction Covers Replacing this part restores properThe Pentair WC9 3 is the OEM replacement black O ring for Sta Rite Posi Flo II pool and spa cartridge filters, keeping the filter housing sealed and operating at full efficiency. IMPORTANT: LUBRICATION REQUIRED SOLD SEPARATELY Always lubricate this O ring with a silicone based lubricant before installation. We carry the Pentair R172351 Lifeguard Silicone Lubricant the OEM matched product for Pentair equipment. This O ring maintains the pressure seal