Value Collection ZMSCS70389 Silicone O-ring Dash 389

Product Description

The VALUE COLLECTION ZMSCS70389 is a round cross-section silicone O-ring sized to Dash 389 specifications. It measures 20 inches inside diameter, 20.375 inches outside diameter, and 0.1875 inches thick. The silicone compound carries a Shore A hardness of 70, placing it in the hard hardness category. This O-ring is rated for service from -80 degrees F to 450 degrees F, making it well suited for applications that demand a wide temperature range and good dry heat resistance. It is white in color and is sold individually. Technicians across HVAC, plumbing, and industrial maintenance install this type of seal during equipment assembly, repair, and preventive maintenance work.

This O-ring is appropriate for use in systems where exposure to oils, chemicals, and solvents is a consideration, though oil resistance is limited. Its silicone construction provides good weather and ozone resistance, which makes it a practical choice for both indoor and outdoor equipment sealing tasks. Typical applications include large-diameter flange faces, access panel seals, pump housings, and fluid system interfaces where a reliable static or low-motion dynamic seal is required. This size is commonly encountered in commercial HVAC equipment, large plumbing assemblies, and industrial process systems.

Key Features

• Silicone compound rated from -80 degrees F to 450 degrees F for wide thermal range service
• Shore A 70 hardness provides firm sealing under compression without excessive deformation
• Round cross-section profile ensures consistent seat contact on standard O-ring grooves
• Good weather and ozone resistance extends service life in outdoor or ventilated environments
• Compatible with oils, chemicals, and solvents; note limited oil resistance in high-concentration oil service
• White silicone color aids visual inspection during assembly and maintenance

Compatibility

Designed as a standard Dash 389 O-ring replacement for any groove machined to AS568 Dash 389 dimensions, with a 20 inches inside diameter and 0.1875 inches cross-section thickness.

Installation Notes

O-ring installation should be performed by a qualified technician following the equipment manufacturer's service procedures. Depressurize and isolate the system before removing any existing seal. Inspect the groove for burrs, debris, or corrosion before seating the new O-ring, and avoid stretching or twisting the ring during installation. Consult applicable mechanical codes and equipment service manuals for torque and assembly specifications not covered here.