Value Collection ZMSCH70155 O-ring 4 in Id Nbr Dash 155 50-pack

Product Description

The VALUE COLLECTION ZMSCH70155 is a Dash 155 O-ring manufactured from Nitrile Butadiene Rubber (Buna-N), the most widely used elastomer in fluid sealing applications. This O-ring measures 4.0000 inches inside diameter, 4.1880 inches outside diameter, and 0.0937 inches (3/32 inches) thick with a round cross section. It carries a Shore A hardness rating of 70, placing it in the hard range for reliable compression set resistance. Licensed HVAC technicians, plumbers, and industrial mechanics use this seal in systems where petroleum-based fluids or lubricants are present. Each order ships in a package quantity of 50 units.

This O-ring is suited for residential and commercial HVAC, plumbing, and hydraulic applications where Buna-N compatibility is required. Its petroleum product resistance makes it a common choice for refrigeration oil circuits, fuel handling assemblies, pneumatic fittings, and hydraulic valve bodies. The Dash 155 designation follows the standard AS568 sizing series, allowing direct cross-reference to OEM seal specifications across a wide range of equipment. It is not recommended for use in systems involving ozone exposure, direct sunlight storage, or near motors and electrical equipment that generate ozone.

Key Features

• Buna-N (Nitrile Butadiene Rubber) construction with excellent resistance to petroleum products
• Dash 155 designation per AS568 standard sizing for broad cross-reference compatibility
• Shore A hardness of 70 for reliable compression set and seal retention
• Operating temperature range of -40 degrees F to 250 degrees F
• Round cross-section profile for standard groove seating
• Meets SAE and MIL-Spec standards

Compatibility

Compatible with petroleum-based products and fluids. Designed as a standard Dash 155 replacement O-ring for use in applications where Buna-N elastomer is specified. Not FDA approved; not suitable for food-contact or potable-water applications where NSF or FDA-grade material is required.

Installation Notes

Installation is performed by licensed HVAC technicians, plumbers, or qualified mechanics depending on the application. Always depressurize and de-energize the system before removing the old seal. Lightly lubricate the O-ring with a compatible fluid or assembly lubricant before seating it in the groove to prevent tearing during installation. Avoid over-stretching the ring; do not store unused O-rings near motors, ozone-generating equipment, or in direct sunlight.