Description
The Pentair 35505-1423Z is the OEM replacement air relief nipple O-ring for the Sta-Rite System 3 D.E., Sand, and Modular Media filter series. This single O-ring seals the air relief nipple assembly on the filter tank, preventing air and water from bypassing the fitting during normal filtration operation.
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.
A failed or deteriorated air relief nipple O-ring allows air to escape around the fitting rather than through the relief valve, and can permit water weeping at the nipple base under system pressure. Replacing this O-ring restores a proper seal at the air relief assembly and is a routine service step whenever the filter head is opened for cleaning or grid inspection.
Specifications
| Pentair Part Number | 35505-1423Z |
| Quantity Included | 1 (Each) |
Fits Into
| Brand | Equipment Line | Model / Part Number | Notes |
| Pentair (formerly Sta-Rite) | System 3 D.E. Filter SD Series | S7D75 | |
| Pentair (formerly Sta-Rite) | System 3 D.E. Filter SD Series | S8D110 | |
| Pentair (formerly Sta-Rite) | System 3 Modular D.E. Filters SMD Series | SMD | System 3 Modular D.E. Filters |
| Pentair (formerly Sta-Rite) | System 3 Modular Media Filter System 3 | S7M120 | |
| Pentair (formerly Sta-Rite) | System 3 Modular Media Filter System 3 | S7M400 | |
| Pentair (formerly Sta-Rite) | System 3 Modular Media Filter System 3 | S8M150 | |
| Pentair (formerly Sta-Rite) | System 3 Modular Media Filter System 3 | S8M500 | |
| Pentair (formerly Sta-Rite) | System 3 Sand Filter System 3 | S7S50 | Verify fitment before ordering |
| Pentair (formerly Sta-Rite) | System 3 Sand Filter System 3 | S8S70 | Verify fitment before ordering |
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
Before installation, apply a thin coat of Pentair R172351 Lifeguard Silicone Lubricant to the O-ring to help it seat evenly, prevent tearing during assembly, and extend service life. Never use petroleum-based lubricants they will degrade the rubber and cause premature failure.
