Value Collection ZMSCH70439 O-ring Dash 439 Nitrile Nbr

Product Description

The VALUE COLLECTION ZMSCH70439 is a Dash 439 O-ring manufactured from Nitrile Butadiene Rubber (Buna-N), one of the most widely used elastomers in fluid sealing applications. It features a round cross section with an inside diameter of 6.5 inches, an outside diameter of 7 inches, and a thickness of 0.25 inches. Rated at 70 Shore A hardness, this O-ring delivers reliable compression set performance along with strong resistance to tear and abrasion. HVAC technicians, plumbers, and industrial maintenance professionals install this seal in systems handling petroleum-based fluids and lubricants.

This O-ring is suited for static and dynamic sealing applications in residential and commercial systems where contact with petroleum products is expected. Typical installations include pump housings, valve bodies, pipe flanges, and hydraulic or refrigeration system fittings that require a large-diameter face or radial seal. The Buna-N compound performs across a working temperature range of -40 degrees F to 250 degrees F, making it appropriate for a broad range of mechanical and fluid-handling environments. Sold in a package quantity of 2.

Key Features

• Buna-N (Nitrile Butadiene Rubber) construction offers excellent resistance to petroleum products and oils
• Round cross section with 6.5 inches ID and 7 inches OD for Dash 439 standard fitment
• 70 Shore A hardness rating provides a hard, durable seal under compression
• Working temperature range of -40 degrees F to 250 degrees F
• Meets SAE and MIL-Spec standards
• Resistant to tear and abrasion; not recommended for ozone or UV exposure environments

Compatibility

Designed for use with petroleum products and compatible fluid systems requiring a Dash 439 O-ring. Compatible material designation includes petroleum-based fluids and lubricants. Not FDA approved; not intended for food-contact or potable-water applications.

Installation Notes

Installation is typically performed by licensed plumbers, HVAC technicians, or industrial mechanics during pump, valve, or fitting service. Power down or depressurize the system completely before removing existing seals. Avoid storing Buna-N O-rings in direct sunlight or near motors and other electrical equipment that may generate ozone, as ozone exposure degrades nitrile rubber. Lubricate the O-ring with a compatible petroleum-based grease during installation to prevent pinching or tearing.