Usa Industrials ZUSAH90908 O-ring Dash 908 Buna-n 100-pack

Product Description

The USA INDUSTRIALS ZUSAH90908 is a Dash 908 Buna-N (Nitrile Butadiene Rubber) O-ring designed for static and dynamic sealing applications across HVAC, plumbing, and fluid-handling systems. It measures 0.644 inches inside diameter, 0.818 inches outside diameter, and 0.087 inches thick with a round cross section. The compound carries a 90 Shore A hardness rating - classified as extra hard - and operates across a temperature range of -40 degrees F to 250 degrees F. This part is sold in a pack of 100 and is installed by HVAC technicians, plumbers, and mechanical contractors requiring a high-volume supply of standard-grade seals.

Buna-N is the most widely used O-ring elastomer in trade applications. This seal is well suited for petroleum-based fluid systems including refrigerant oil circuits, hydraulic assemblies, fuel lines, and general plumbing connections where exposure to oils, fuels, and lubricants is expected. The extra-hard durometer provides strong resistance to compression set, tear, and abrasion, making it reliable in high-cycle or pressurized service environments. It is not recommended for systems using strong oxidizers, ozone-rich environments, or applications requiring FDA compliance.

Key Features

• Buna-N (NBR) elastomer - excellent resistance to petroleum products, oils, and fuels
• 90 Shore A hardness (extra hard) - resists compression set, tear, and abrasion
• Round cross section - 0.087 inches thick, Dash 908 standard sizing
• Operating temperature range: -40 degrees F to 250 degrees F
• Black color, standard grade
• Pack of 100 pieces - suitable for stocking or high-volume service work
• Should not be stored in direct sunlight or near motors or electrical equipment that generates ozone

Compatibility

Compatible with petroleum products and petroleum-based fluid systems. Designed as a standard Dash 908 Buna-N O-ring suitable for OEM-style replacement or new installation in HVAC, plumbing, and mechanical fluid-handling assemblies where NBR elastomer is specified.

Installation Notes

Installation is performed by HVAC technicians, plumbers, or mechanical contractors. Always depressurize and isolate the system before removing or installing any O-ring seal. Lightly lubricate the O-ring with a compatible petroleum-based lubricant prior to installation to prevent tearing during assembly. Inspect the seating groove for damage or debris before installing the new seal.