Value Collection ZMSCH90251 O-ring Dash 251 Nitrile 90D

Product Description

The VALUE COLLECTION ZMSCH90251 is a Dash 251 O-ring made from Nitrile Butadiene Rubber (Buna-N), the most widely used elastomer in fluid sealing applications. It measures 5.125 inches inside diameter, 5.375 inches outside diameter, and 0.125 inches thick with a round cross section. Rated at 90 durometer (extra hard), it delivers excellent resistance to petroleum-based fluids along with strong compression set, tear resistance, and abrasion resistance. The operating temperature range runs from -40 degrees F to 250 degrees F. Licensed plumbers, pipefitters, hydraulic technicians, and maintenance mechanics install this type of seal across a broad range of industrial and mechanical assemblies.

This O-ring is suited for static and dynamic sealing applications where petroleum product exposure is a primary concern. Typical installation scenarios include hydraulic cylinders, pumps, valves, pipe flanges, and fluid fittings in residential, commercial, and industrial settings. The Buna-N compound resists oils, fuels, and many hydraulic fluids. It is not recommended for use with ozone-generating environments or in direct sunlight storage conditions. Meets SAE and MIL-Spec standards, making it appropriate for both commercial maintenance and specification-driven work.

Key Features

• Buna-N (Nitrile Butadiene Rubber) material with excellent resistance to petroleum products and hydraulic fluids
• 90 durometer extra hard rating for high-compression sealing applications
• Operating range from -40 degrees F to 250 degrees F
• Round cross section, Dash 251 standard sizing
• Meets SAE and MIL-Spec standards
• Package quantity of 25 units per order

Compatibility

Compatible with petroleum products, hydraulic oils, fuels, and similar fluid media. Designed as a standard Dash 251 replacement O-ring for hydraulic, pneumatic, and fluid system components requiring a 5.125 inch inside diameter Buna-N seal.

Installation Notes

Installation is typically performed by licensed plumbers, pipefitters, or hydraulic system technicians. Always depressurize and drain the system before removing or installing any O-ring seal. Lubricate the O-ring with a compatible fluid or assembly lubricant to prevent twisting or tearing during installation. Do not store Buna-N O-rings near motors, electrical equipment, or in direct sunlight, as ozone and UV exposure degrade the elastomer over time.