Part number 90-423-7113 is a generic Buna-N O-ring (O-47/AS568 #113) with a 9/16" inner diameter and 3/32" cross-section.
This highly standardized part is used across a vast array of pool and spa equipment from many different component manufacturers.
Hot tub manufacturers who use original equipment from the following component suppliers will utilize this O-ring in various applications, such as internal valve shafts, diverters, and specific filter parts:
Pentair: This O-ring is used in specific Pentair/Purex/PacFab 2" PVC and Trimline valves, as well as some filter and pool cleaner components.
Waterway Plastics: Used in select Waterway spa parts, including certain diverters and valve stems.
Balboa Water Group / HydroAir: Found in some Hydroflow 3-Way valves and Micro-massage wall fittings.
Hayward: Used in various Hayward pool components, such as certain valve stems and filter parts.
Hydropool: This specific part number is listed as a generic replacement item on the Hydropool website, indicating its use in their systems.
Since the O-ring is a universal plumbing component, many different hot tub brands that source their valves and plumbing from the above manufacturers will use this part.
