Value Collection ZMSCH90321 O-ring Dash 321 Nbr

Product Description

The VALUE COLLECTION ZMSCH90321 is a Dash 321 nitrile butadiene rubber (Buna-N) O-ring used to create reliable fluid and pressure seals in a wide range of mechanical assemblies. It measures 1.188 inches inside diameter, 1.563 inches outside diameter, and 0.1875 inches thick with a round cross section. Rated at 90 durometer (extra hard), this O-ring handles operating temperatures from -40 degrees F to 250 degrees F and is compatible with petroleum-based fluids. Buna-N is the most widely used O-ring elastomer and offers excellent compression set resistance along with strong tear and abrasion resistance. Plumbers, HVAC technicians, and mechanical maintenance professionals install this part in hydraulic, pneumatic, and fluid-handling systems.

This O-ring is suited for residential and commercial applications involving petroleum-based media, including hydraulic cylinders, pump housings, valve stems, and fluid fittings. The extra-hard 90 durometer rating makes it appropriate for higher-pressure sealing applications where softer compounds may extrude. It is not FDA approved and should not be exposed to ozone-generating sources such as electric motors or direct sunlight during storage, as ozone degrades nitrile rubber over time. It meets SAE and MIL-Spec standards, making it a recognized choice for both commercial maintenance and OEM replacement use.

Key Features

• Buna-N (nitrile butadiene rubber) construction with excellent resistance to petroleum products
• 90 durometer extra-hard rating for high-pressure sealing applications
• Operating temperature range of -40 degrees F to 250 degrees F
• Round cross section, Dash 321 standard sizing
• Meets SAE and MIL-Spec standards
• Strong tear and abrasion resistance with excellent compression set performance

Compatibility

Compatible with petroleum-based products and fluids. Designed as a standard Dash 321 O-ring replacement for hydraulic, pneumatic, and fluid-handling assemblies that require a 1.188 inch ID nitrile seal rated to SAE and MIL-Spec standards.

Installation Notes

Installation is typically performed by licensed plumbers, HVAC technicians, or mechanical maintenance professionals. Always depressurize and drain the system before removing or replacing O-rings to prevent fluid release or injury. Lightly lubricate the O-ring with a compatible petroleum-based lubricant before seating to prevent tearing during assembly. Do not store unused O-rings near electric motors, ozone-generating equipment, or in direct sunlight, as ozone exposure degrades nitrile rubber.