Value Collection ZMSCH90250 O-ring Dash 250 Buna-n

Product Description

The VALUE COLLECTION ZMSCH90250 is a Dash 250 Buna-N (Nitrile Butadiene Rubber) O-ring designed for static and dynamic sealing applications across plumbing, hydraulic, pneumatic, and fluid-handling systems. It measures 5 inches inside diameter, 5.25 inches outside diameter, and 0.125 inches thick with a round cross section. Rated at 90 durometer (extra hard), it delivers firm compression set resistance along with strong tear and abrasion resistance. The operating temperature range spans -40 degrees F to 250 degrees F, making it suitable for a broad range of service environments. Licensed plumbers, pipefitters, and maintenance technicians install this O-ring where a reliable petroleum-compatible seal is required.

This O-ring is suited for residential and commercial sealing applications involving petroleum-based fluids, oils, fuels, and hydraulic media. Its Buna-N elastomer compound is the most widely used O-ring material in trade service, particularly in valve bodies, pump housings, fittings, cylinders, and pipe unions. It conforms to SAE and MIL-Spec standards, which makes it appropriate for demanding industrial and mechanical service installations. The Dash 250 designation is a standard AS568 cross-reference size, simplifying drop-in replacement sourcing across common hardware and fitting platforms.

Key Features

• Buna-N (Nitrile Butadiene Rubber) compound with excellent resistance to petroleum products, oils, and fuels
• 90 durometer extra-hard rating provides firm compression set and strong abrasion resistance
• Operating range of -40 degrees F to 250 degrees F suits a wide variety of service conditions
• Round cross section, 0.125 inches thick, conforms to standard Dash 250 AS568 sizing
• Meets SAE and MIL-Spec standards
• Black color; sold in packages of 25 units

Compatibility

Compatible with petroleum products, hydraulic oils, fuels, and related media. Designed as a standard Dash 250 O-ring replacement for valves, pumps, fittings, cylinders, and other fluid-handling components that specify a Buna-N seal at this cross-section size. Not recommended for applications involving ozone, direct sunlight exposure, or equipment that generates ozone such as electric motors.

Installation Notes

Installation is typically performed by licensed plumbers, pipefitters, hydraulic technicians, or qualified maintenance personnel. Depressurize and drain the system fully before removing any fittings or housings containing this O-ring. Lubricate the O-ring with a compatible petroleum-based or system-fluid lubricant before seating to prevent tearing during assembly. Do not store O-rings in direct sunlight or near motors or other electrical equipment that may generate ozone, as this degrades the elastomer over time.