Value Collection ZMSCH90236 O-ring Dash 236 Nbr 90A 50-pack

Product Description

The VALUE COLLECTION ZMSCH90236 is a Dash 236 Nitrile Butadiene Rubber (Buna-N) O-ring sized at 3.25 inches inside diameter, 3.5 inches outside diameter, and 0.125 inches thick with a round cross section. Rated at 90 durometer (extra hard), this O-ring is engineered for static and dynamic sealing applications involving petroleum-based fluids and gases. The Buna-N elastomer compound delivers excellent compression set resistance along with strong tear and abrasion resistance, making it the most commonly specified O-ring material across HVAC, plumbing, hydraulic, and pneumatic systems. The operating temperature range spans -40 degrees F to 250 degrees F. Licensed HVAC technicians, plumbers, and pipefitters regularly stock this size for routine maintenance and emergency repairs.

This O-ring is suited for residential and commercial applications where petroleum-product compatibility is required. Typical uses include pump shaft seals, valve stem packing, refrigerant service port seals, hydraulic cylinder end caps, and threaded pipe fitting face seals. The extra-hard 90 durometer rating makes it appropriate for higher-pressure dynamic applications where a softer compound would extrude or fail prematurely. Sold in a package quantity of 50, this SKU is well suited for service contractors and shop stockrooms maintaining inventory of common Dash 236 seals. Note: Buna-N should not be used with synthetic lubricants, ketones, esters, or strong acids.

Key Features

• Buna-N (Nitrile) elastomer — the most widely used O-ring material for petroleum-product compatibility
• 90 durometer extra-hard rating for reduced extrusion risk in dynamic and high-pressure sealing environments
• Wide temperature range: -40 degrees F to 250 degrees F
• Round cross section, 0.125 inches thick, conforming to Dash 236 standard sizing
• Meets SAE and MIL-Spec standards
• Package of 50 units minimizes per-unit cost for high-volume service operations

Compatibility

Designed for use with petroleum products including hydraulic oils, fuels, and mineral-based lubricants. Compatible material designation per supplier data is Petroleum Products. Conforms to SAE and MIL-Spec O-ring standards for Dash 236 sizing. Not compatible with synthetic esters, ketones, or strong oxidizing agents. FDA approval status: No.

Installation Notes

O-ring replacement is performed by licensed HVAC technicians, journeyman plumbers, or hydraulic system mechanics depending on the application. Before service, de-energize any electrical components, relieve system pressure, and isolate the fluid circuit at the appropriate shutoff valve. Inspect the seating groove for nicks, burrs, or corrosion before installing the new O-ring, and apply a thin film of compatible lubricant to the O-ring to reduce installation stress and prevent initial dry-run damage. Do not store Buna-N O-rings in direct sunlight or near motors, transformers, or other equipment that generates ozone, as ozone exposure degrades nitrile rubber.