Value Collection ZMSCS70443 Silicone O-ring Dash 443

Product Description

The VALUE COLLECTION ZMSCS70443 is a Dash 443 silicone O-ring designed for static and dynamic sealing applications across HVAC, plumbing, industrial, and fluid-handling systems. It measures 7.5 inches inside diameter, 8 inches outside diameter, and 0.25 inches thick with a round cross section. The silicone compound delivers a wide service temperature range from -80 degrees F to 450 degrees F, making it suitable for high-heat environments where standard EPDM or Buna-N rings would fail. Shore hardness is rated at 70, placing it in the hard range for firm compression without excessive deformation under load.

This O-ring is used in residential and commercial applications where exposure to dry heat, weather, ozone, and moderate chemical contact is expected. Typical installation scenarios include pump housings, valve bodies, pipe flanges, and equipment covers in HVAC, pool and spa, and light industrial equipment. It offers limited oil resistance and is not recommended as a primary seal in petroleum-based fluid systems. Installers in plumbing, HVAC, and mechanical trades reach for this profile when replacing deteriorated Dash 443 seals on larger-diameter assemblies.

Key Features

• Wide temperature range: -80 degrees F to 450 degrees F continuous service
• Round cross section, 0.25 inches thick, for consistent radial and face-seal compression
• Shore 70 hardness rated hard for firm seating under bolt or clamp load
• Compatible with oils, chemicals, and solvents in moderate-exposure applications
• Good weather and ozone resistance for outdoor or exposed installations
• Recommended for applications requiring good dry heat resistance

Compatibility

Designed as an OEM-style replacement Dash 443 O-ring for any assembly requiring a 7.5-inch ID, 8-inch OD, 0.25-inch thick round-cross-section silicone seal.

Installation Notes

Licensed plumbers, HVAC technicians, and mechanical service professionals typically install seals of this type. Before replacing the O-ring, depressurize and drain the affected system completely and allow components to cool to ambient temperature. Clean the gland of debris, old lubricant, and seal fragments before seating the new ring. Apply an appropriate silicone-compatible lubricant to ease installation and prevent tearing during assembly.