Value Collection ZMSCH70156 O-ring Dash 156 Nbr 70 Duro 25pk

Product Description

The VALUE COLLECTION ZMSCH70156 is a Dash 156 Nitrile Butadiene Rubber (NBR/Buna-N) O-ring with a round cross section, sized at 4.25 inches inside diameter, 4.438 inches outside diameter, and 0.0937 inches thick. Rated at 70 Shore A hardness, it delivers firm compression set resistance along with strong tear and abrasion resistance. The NBR compound is the most widely used O-ring elastomer in industrial and fluid-system applications, offering excellent resistance to petroleum-based fluids and lubricants. Licensed plumbers, HVAC technicians, and maintenance mechanics install this type of seal in hydraulic assemblies, pneumatic fittings, and fluid-handling components where reliable static or dynamic sealing is required. Package quantity is 25 rings per order.

This O-ring is suited for residential and commercial maintenance applications involving petroleum-based fluids, hydraulic oils, fuels, and general lubricants. It performs across a temperature range of -40 degrees F to 250 degrees F, making it appropriate for a broad range of service environments. The Dash 156 designation corresponds to a standard AS568 size, allowing straightforward cross-referencing in groove-spec documentation and OEM seal kits. Typical install scenarios include pump seals, valve bodies, fluid fittings, and manifold gasket grooves in HVAC, plumbing, and general mechanical systems. The black color aids visual inspection during service. This part meets SAE and MIL-Spec standards. Note: not FDA approved and should not be stored in direct sunlight or near motors or electrical equipment that generates ozone.

Key Features

• NBR/Buna-N compound offers excellent resistance to petroleum products, hydraulic oils, and fuels
• 70 Shore A hardness rating provides firm compression set and reliable sealing under pressure
• Dash 156 standard AS568 sizing for easy groove-spec cross-referencing
• Operating temperature range of -40 degrees F to 250 degrees F suits a wide variety of service conditions
• Round cross section with 0.0937-inch thickness ensures consistent groove fit and seal integrity
• Meets SAE and MIL-Spec standards; sold in a package of 25

Compatibility

Designed as a standard Dash 156 replacement O-ring compatible with petroleum-based fluid systems. Consult the equipment manufacturer groove specifications to confirm fit before installation.

Installation Notes

Installation is typically performed by licensed plumbers, HVAC technicians, or qualified maintenance mechanics. Power down or depressurize the system completely and relieve all fluid pressure before removing the existing seal. Lightly lubricate the O-ring with a compatible fluid or petroleum-based grease before seating it in the groove to avoid pinching or tearing during assembly. Do not store unused O-rings in direct sunlight or near ozone-generating equipment such as motors or electrical panels, as ozone degrades NBR compounds over time.