Value Collection ZMSCH90350 O-ring Dash 350 Buna-n 90 Duro

Product Description

The VALUE COLLECTION ZMSCH90350 is a Dash 350 Buna-N (Nitrile Butadiene Rubber) O-ring used to create reliable fluid seals in hydraulic, pneumatic, plumbing, and HVAC applications. It measures 4.625 inches inside diameter, 5 inches outside diameter, and 0.1875 inches thick with a round cross-section. Rated at 90 durometer (extra hard), this O-ring handles a temperature range of -40 to 250 degrees F and is compatible with petroleum-based fluids. Buna-N is the most widely used O-ring elastomer in trade applications, chosen for its excellent compression set, tear resistance, and abrasion resistance. Sold in packages of 10.

This O-ring is suited for residential and commercial plumbing, HVAC equipment, hydraulic assemblies, and other systems that handle petroleum products or oils. The Dash 350 size is a standard AS568 designation, making it a common replacement in pumps, valves, fittings, and manifold assemblies. Plumbers, pipefitters, HVAC technicians, and millwrights regularly install this size when servicing fluid-handling equipment that requires a durable, large-diameter static or dynamic seal.

Key Features

• Buna-N (Nitrile) elastomer — excellent resistance to petroleum products and oils
• 90 durometer extra-hard rating for high-pressure sealing applications
• Wide temperature range: -40 to 250 degrees F
• Round cross-section, Dash 350 standard size
• Meets SAE and MIL-Spec standards
• Package quantity of 10 per order

Compatibility

Compatible with petroleum products and petroleum-based fluids. Designed as a standard Dash 350 O-ring replacement for pumps, valves, hydraulic fittings, and HVAC equipment requiring a 4.625-inch ID seal. Not FDA approved; not recommended for ozone-rich environments or direct sunlight exposure.

Installation Notes

Installation is typically performed by licensed plumbers, pipefitters, or HVAC technicians. Always relieve system pressure and shut off fluid supply before removing old seals or installing new O-rings. Inspect the mating groove for nicks, burrs, or corrosion before seating the O-ring. Avoid storing Buna-N O-rings near motors, electrical equipment, or direct sunlight, as ozone and UV exposure can degrade the material.