Value Collection ZMSCH70MD239 O-ring Dash 239 Buna-n 5-pack

Product Description

The VALUE COLLECTION ZMSCH70MD239 is a Dash 239 O-ring made from Nitrile Butadiene Rubber (Buna-N), the most widely used elastomer in sealing applications. It measures 3.609 inches inside diameter, 3.875 inches outside diameter, and 0.125 inches thick with a round cross section. Rated at 70 Shore A hardness, this O-ring delivers reliable sealing performance across a broad temperature range of -40 degrees F to 250 degrees F. It is sold in a pack of 5 and is installed by plumbers, pipefitters, HVAC technicians, and maintenance professionals working on fluid or pneumatic systems involving petroleum-based media.

Buna-N O-rings in the Dash 239 size are commonly used in hydraulic fittings, fuel systems, compressor assemblies, pneumatic cylinders, and valve bodies where petroleum product exposure is expected. This size is a standard AN/MS dash number used across industrial, commercial HVAC, and plumbing applications. The round cross section seats into standard O-ring grooves machined to Dash 239 tolerances.

Key Features

• Nitrile Butadiene Rubber (Buna-N) construction offers excellent resistance to petroleum products, oils, and fuels
• 70 Shore A hardness rating provides a firm, durable seal with strong compression set resistance
• Operating temperature range of -40 degrees F to 250 degrees F suits a wide range of service environments
• Round cross section conforms to standard Dash 239 groove dimensions
• Good tear and abrasion resistance for long service life in dynamic and static applications
• Pack of 5 units per order; minimum order quantity of 1 pack

Compatibility

Designed for use in systems and assemblies that are compatible with petroleum products and other media suitable for Buna-N elastomers. Fits standard Dash 239 O-ring grooves. Not approved for FDA food-contact applications.

Installation Notes

Installation should be performed by a qualified technician familiar with sealing system requirements. Before installing, de-energize the system and relieve all pressure from hydraulic or pneumatic lines per applicable safety procedures. Lightly lubricate the O-ring with a petroleum-compatible lubricant to ease installation and prevent rolling or twisting in the groove. Do not store O-rings in direct sunlight or near motors or other electrical equipment that may generate ozone, as this degrades Buna-N material over time.