Value Collection ZMSCH90259 O-ring Dash 259 Nbr 90D

Product Description

The VALUE COLLECTION ZMSCH90259 is a Dash 259 Buna-N (Nitrile Butadiene Rubber) O-ring rated at 90 durometer, classified as extra hard. It measures 6.25 inches inside diameter, 6.5 inches outside diameter, and 0.125 inches thick with a round cross-section profile. The operating temperature range spans -40 to 250 degrees F, making it suitable for demanding fluid-sealing applications. This O-ring meets SAE and MIL-Spec standards and is sold in a package quantity of 10 units. Plumbers, pipefitters, and mechanical technicians install this part in systems where reliable sealing around petroleum-based fluids is required.

This O-ring is designed for use in applications involving petroleum products, hydraulic fluids, and similar media. Its Buna-N compound provides excellent resistance to petroleum-based oils and fuels, making it a common choice in hydraulic cylinders, pipe flanges, pump housings, and valve assemblies found in commercial and industrial plumbing, HVAC equipment, and fluid-handling systems. The extra-hard 90 durometer rating suits high-pressure environments where softer compounds would extrude or deform under load. Package quantity of 10 supports field service kits and maintenance stock.

Key Features

• Buna-N (NBR) compound: the most widely used O-ring elastomer, with excellent resistance to petroleum products
• 90 durometer extra-hard rating for use in high-pressure sealing applications
• Temperature range of -40 to 250 degrees F for broad service compatibility
• Excellent compression set, tear resistance, and abrasion resistance
• Meets SAE and MIL-Spec standards
• Sold in a package of 10 units (minimum order quantity: 1)

Compatibility

Compatible with petroleum products and similar hydrocarbon-based media. Designed as an OEM-style replacement or service O-ring for applications requiring a Dash 259 cross-section in Buna-N rubber. Not recommended for storage in direct sunlight or near motors and other electrical equipment that may generate ozone.

Installation Notes

Shut down and de-pressurize the system fully before removing the old O-ring or installing this replacement. Lightly lubricate the O-ring with a compatible lubricant prior to seating to prevent tearing during installation. Avoid rolling or twisting the ring as it is seated into the groove. Verify the groove dimensions match the Dash 259 cross-section before installation to ensure proper compression and sealing.