Value Collection ZMSCH70253 O-ring Dash 253 Nbr 70 Duro

Product Description

The VALUE COLLECTION ZMSCH70253 is a Dash 253 O-ring made from Nitrile Butadiene Rubber (NBR, also known as Buna-N), designed for static and dynamic sealing applications in fluid and pneumatic systems. It measures 5.375 inches inside diameter by 5.625 inches outside diameter with a 0.125-inch cross-section thickness. The round cross-section profile seats reliably in standard AN/MS grooves sized for a Dash 253 ring. At 70 Shore A hardness, it provides a firm, reliable seal with good compression set resistance, tear strength, and abrasion resistance. Plumbers, pipefitters, HVAC technicians, and fluid-power mechanics install this type of ring across a wide range of petroleum-based fluid and air service applications.

This O-ring is suited for use in hydraulic systems, pneumatic assemblies, pumps, valves, cylinders, and pipe fittings where compatibility with petroleum-based fluids and oils is required. The NBR compound offers reliable sealing across a service temperature range of -40 degrees F to 250 degrees F, making it appropriate for both refrigerated and moderate high-temperature process lines. Sold in a package quantity of 10 rings, it is a practical stock item for shops and field service kits where the Dash 253 size is a common fitment.

Key Features

• Buna-N (NBR) elastomer — excellent resistance to petroleum products, oils, and fuels
• 70 Shore A hardness rating provides firm sealing with good compression set performance
• Round cross-section profile fits standard Dash 253 AN/MS O-ring grooves
• Operating temperature range: -40 degrees F to 250 degrees F
• Tear and abrasion resistance extends service life in dynamic sealing applications
• Meets SAE and MIL-Spec standards for dimensional and material compliance
• Package quantity of 10 rings per order

Compatibility

Designed as a standard Dash 253 replacement O-ring compatible with petroleum products and suitable for use in hydraulic, pneumatic, and fluid-transfer assemblies requiring a 5.375-inch ID NBR seal. Not recommended for use with ozone-generating equipment, in direct sunlight storage, or in applications requiring FDA-approved materials.

Installation Notes

Depressurize and isolate the system completely before removing the old O-ring or installing a replacement. Lightly lubricate the ring with a compatible fluid or O-ring lubricant before seating it to prevent tearing during assembly. Avoid twisting or rolling the ring into the groove — seat it evenly around the full circumference. Inspect the groove for nicks or corrosion that could compromise the seal before installation.