ARO Y325-111 Nitrile / Buna-N O-Ring | Genuine Pump Service Component

ARO Y325-111 Buna-N O-Ring

The ARO Y325-111 is a Buna-N replacement O-ring used in compatible ARO diaphragm pump fluid sections. ARO parts documentation specifies the seal as 3/32 inch cross-section x 5/8 inch outside diameter.

It is commonly associated with compatible 1/2-inch metallic and non-metallic diaphragm pump families and is identified as Item 2 in applicable ARO parts documentation.

Buna-N / Nitrile Material

The Y325-111 uses Buna-N, also known as Nitrile or NBR. This elastomer is commonly selected for sealing duties involving compatible oils and industrial process fluids.

Before installation, confirm that Buna-N is suitable for the actual fluid chemistry, concentration and temperature of the application.

Verified Dimensions

• Cross-section: 3/32 inch
• Outside diameter: 5/8 inch

Because many ARO O-rings have similar appearances, the manufacturer part number and documented dimensions should both be checked during parts selection.

Compatible Pump Applications

ARO documentation shows Y325-111 in compatible 66605X pump configurations, including selected polypropylene, groundable acetal and PVDF versions.

Replacement-parts references also identify Y325-111 for compatible 1/2-inch metallic and non-metallic ARO diaphragm pumps.

Fluid-Section Item 2

The Y325-111 appears as Item 2 in applicable fluid-section parts diagrams. This reference can help maintenance personnel locate the O-ring during pump disassembly and rebuild operations.

Documented Assembly Quantity

Applicable ARO documentation lists one Y325-111 O-ring in the pump assembly.

This is an assembly quantity and should not be interpreted automatically as the supplier sales-package quantity.

Inspection During Maintenance

When servicing the pump, inspect the existing O-ring for flattening, cuts, cracking, hardening, swelling or chemical damage.

Also inspect the mating surfaces and nearby components. Installing a new O-ring against a damaged sealing surface may not correct the original leakage problem.

Ordering Guidance

Before purchasing, verify:

• ARO part number Y325-111
• Complete diaphragm pump model
• Buna-N / Nitrile compatibility
• 3/32 inch x 5/8 inch OD dimensions
• Required service quantity

Using the exact manufacturer part number helps ensure the correct O-ring is selected for the intended pump position.