The Waterway 805‑0435 O‑Ring (#435) is a genuine OEM replacement seal designed for use with Sand Filter multi-port valves from Waterway. Constructed from durable rubber and precision-sized to re-establish a leak free seal, it helps maintain proper filtration and operation of your pool equipment. 

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Key Features

• OEM Part #: 805-0435 (also referenced as #435) for Waterway multi-port valves. 

• Internal Diameter (ID): approximately 5 5/8″ (5.625″) with a 5/16″ cross section. 

• Designed for use in sand filter applications and multi-port valve collar assemblies. 

• High quality rubber construction suited for pool chemistry and outdoor exposure. 

• Quick, drop in replacement helps restore valve sealing and reduce bypass or leaks.

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Product Overview
Over time, the collar O-ring on a sand filter’s multi-port valve can become worn, compressed or deteriorate leading to leaks, inefficient filtration, or premature drain down of water through the valve body. Replacing the O-ring with the 805-0435 helps restore proper sealing, ensuring the valve directs flow correctly for filtration, back wash, rinse and other cycles.

For pool service professionals and maintenance kits, this O-ring is a critical consumable part small, inexpensive, but vital for system integrity. In an ecommerce catalog, position it under “Filter Multi-Port Valve Parts” or “Sand Filter Replacement Seals” and highlight that it’s OEM-specified for Waterway systems. Since dimensions matter (ID/Cross-Section), listing the size (5 5/8″ ID x 5/16″) ensures compatibility.