Value Collection ZMSCH70440 O-ring Dash 440 Nitrile 70A

Product Description

The VALUE COLLECTION ZMSCH70440 is a Dash 440 O-ring manufactured from Nitrile Butadiene Rubber (Buna-N), the most widely used elastomer in sealing applications. It features a 6.75-inch inside diameter, 7.25-inch outside diameter, and a round cross-section thickness of 0.25 inches. Rated at 70 Shore A hardness, this O-ring delivers excellent resistance to petroleum-based fluids, outstanding compression set performance, and strong tear and abrasion resistance. It is suited for static and dynamic sealing in fluid-handling systems operating between -40 degrees F and 250 degrees F. Licensed tradespeople and maintenance technicians install this type of seal during routine service and equipment overhaul.

This O-ring is appropriate for use in hydraulic systems, plumbing assemblies, fuel systems, and general industrial equipment where petroleum product exposure is expected. Its Buna-N compound makes it a standard choice for HVAC, refrigeration, and fluid-power applications that demand consistent sealing under pressure cycling and temperature variation. It is not recommended for exposure to ozone, direct sunlight during storage, or environments near motors and electrical equipment that generate ozone. The package quantity is 2 rings per order.

Key Features

• Buna-N (Nitrile Butadiene Rubber) construction — the industry standard elastomer for petroleum-fluid sealing
• 70 Shore A hardness rating — classified as hard, providing strong resistance to extrusion under pressure
• Wide service temperature range: -40 degrees F to 250 degrees F
• Excellent compression set and tear and abrasion resistance for extended service life
• Round cross-section profile conforms to SAE and MIL-Spec standards
• Sold in packages of 2, with a minimum order quantity of 1 package

Compatibility

Compatible with petroleum products and petroleum-based hydraulic fluids. Meets SAE and MIL-Spec standards for O-ring materials and dimensions. Not compatible with ozone-generating environments, strong oxidizing agents, or storage conditions involving direct sunlight.

Installation Notes

Installation is typically performed by licensed plumbers, hydraulic technicians, HVAC mechanics, or industrial maintenance personnel. Always depressurize and drain the system before removing or replacing any sealing component. Lubricate the O-ring with a compatible petroleum-based or system-appropriate lubricant prior to seating to reduce installation stress and prevent damage to the cross-section. Do not store O-rings near motors, electrical equipment, or in direct sunlight, as ozone and UV exposure degrade Buna-N elastomers over time.