Value Collection ZMSCH70351 O-ring Dash 351 Nbr

Product Description

The VALUE COLLECTION ZMSCH70351 is a Dash 351 O-ring manufactured from Nitrile Butadiene Rubber (Buna-N), the most widely used elastomer in sealing applications. It measures 4.75 inches inside diameter, 5.125 inches outside diameter, and 0.1875 inches thick, with a round cross section and a Shore A hardness of 70. Buna-N compound delivers excellent resistance to petroleum-based fluids, strong compression set retention, and solid tear and abrasion resistance. This O-ring is sold in a package quantity of five and is suitable for use across HVAC, plumbing, hydraulic, and fluid-handling systems where petroleum-product exposure is a primary sealing concern.

This O-ring is used in applications that require a reliable static or dynamic seal in environments with petroleum oils, fuels, or hydraulic fluids. It performs across a service temperature range of -40 degrees F to 250 degrees F, making it appropriate for residential and light commercial mechanical systems. Typical installations include pump housings, valve bodies, pipe fittings, and fluid-system couplings. Licensed plumbers, HVAC technicians, and industrial maintenance professionals commonly specify Buna-N O-rings for these service conditions. Avoid installing this part in applications with ozone, strong oxidizing agents, or aromatic solvent exposure, as Buna-N is not suited for those environments.

Key Features

• Nitrile Butadiene Rubber (Buna-N) construction with excellent petroleum-product resistance
• Dash 351 standard sizing: 4.75 inches ID, 5.125 inches OD, 0.1875 inches thick
• Shore A hardness of 70 with hard hardness rating for positive sealing under compression
• Operating temperature range of -40 degrees F to 250 degrees F
• Round cross section for consistent sealing in standard O-ring grooves
• Meets SAE and MIL-Spec standards

Compatibility

Designed for use with petroleum products and petroleum-based hydraulic fluids. Compatible with standard Dash 351 O-ring groove dimensions per SAE and MIL-Spec requirements. Not compatible with ozone-generating equipment, aromatic solvents, or strong oxidizing media. Store away from direct sunlight and electrical equipment that may generate ozone.

Installation Notes

O-rings should be installed by a qualified technician familiar with the system being serviced. De-energize, depressurize, and drain the system before replacing any seals. Inspect the mating groove for burrs, scoring, or contamination before installation, and apply a compatible lubricant to ease seating without distorting the ring. Avoid twisting or rolling the O-ring during installation, as this can compromise the seal.