ARO Y325-126 Buna-N O-Ring | 3/32 in. x 1-9/16 in. OD Pump Seal

Identify the Correct ARO Replacement Seal

The ARO Y325-126 Buna-N O-Ring is a replacement component for compatible ARO diaphragm pump assemblies. Burt Process identifies Y325-126 as an ARO O-ring and references the 66610X-XXX-C pump family. For buyers sourcing a maintenance part, the manufacturer’s part number provides a more useful starting point than a general description such as “pump seal” or “replacement rubber ring.”

Check Dimensions and Material Together

ARO specifies this component as nitrile, with nominal dimensions of 3/32 inch across the ring’s cross-section and 1-9/16 inches across its outside diameter. Nitrile is also commonly described as Buna-N. Use the part number, material and dimensions together when reviewing a replacement; approximate visual similarity should not be the deciding factor.

Match the Seal to Its Assembly Position

The 1-inch metallic pump documentation lists six Y325-126 O-rings at air-motor item 114. For specified -XX1 and -XX2 fluid-section configurations, it lists four at item 19. These figures describe the documented assembly requirements, not the package quantity of an individual product listing.

Fluid-section selection is also material-specific. The same manual identifies Y327-126 as Viton and Y328-126 as PTFE for other configurations. Y325-126 should therefore not be treated as an automatic substitute for either part simply because the size designation is similar.

Plan the Parts Needed for Maintenance

Consider whether the job calls for one replacement component or a more extensive service kit. ARO identifies 637118-C for air-section servicing and 637119-XX-C for the applicable fluid-section repairs in this pump family. Check the full model configuration before selecting a kit, especially when the repair involves diaphragms, balls or other fluid-contact components.

For your purchasing request, include the equipment model, the assembly being repaired, the Y325-126 part number and the required quantity. Also note any additional components identified during inspection. This keeps the order tied to the actual maintenance task rather than an assumed universal fit.

Review the Operating Conditions

A dimensionally matching seal is not necessarily suitable for every fluid or cleaning process. Consult ARO’s chemical compatibility guidance and verify material suitability for the actual application. Chemical exposure can affect usable temperature limits, so a general material rating should not replace an application-specific check.

Use ARO Y325-126 as the purchasing reference when your pump’s documentation calls for this nitrile O-ring. Confirm fitment and quantity before ordering, then follow the relevant manufacturer’s service procedure during installation.