Ever-tite 312GSKBUMS Square O-ring Dash 312 Nitrile Buna-n

Product Description

The EVER-TITE COUPLING PRODUCTS 312GSKBUMS is a square cross-section O-ring designed for fluid sealing applications in plumbing, HVAC, and industrial service. Manufactured from Nitrile Butadiene Rubber (Buna-N), this black elastomeric seal measures 1.359 inches inside diameter and 1.938 inches outside diameter with a 0.25-inch thickness. The square cross-section profile provides increased sealing surface contact compared to a standard round cross-section, making it well-suited for static face-seal and groove-seat applications. It carries a Dash 312 designation per standard O-ring sizing conventions. Licensed tradespeople and experienced service technicians working on fluid system components are the primary installers.

This O-ring is appropriate for use in systems where petroleum-based oils and hydraulic fluids are present. Buna-N compound maintains sealing integrity across a working temperature range of -40 degrees F to 212 degrees F, covering the majority of residential and light commercial HVAC, plumbing, and pool equipment service environments. It is sold as a single unit and is compatible with systems requiring a Dash 312 nominal 1-1/4-inch O-ring seat. Its black color is standard for Buna-N seals and aids visual identification during installation and inspection.

Key Features

• Square cross-section increases sealing contact area in static groove applications
• Nitrile Butadiene Rubber (Buna-N) material rated for compatibility with petroleum-based oils
• Wide service temperature range: -40 degrees F to 212 degrees F
• Dash 312 designation for straightforward cross-reference to standard O-ring sizing charts
• Inside diameter 1.359 inches, outside diameter 1.938 inches, thickness 0.25 inches
• Weighs approximately 0.016 pounds - lightweight, single-piece replacement seal

Compatibility

Designed as an OEM-style replacement seal for any assembly specifying a Dash 312 square cross-section Buna-N O-ring with a nominal 1-1/4-inch seat.

Installation Notes

Install by a qualified plumber, HVAC technician, or pool service professional. Before replacing any O-ring, shut off fluid flow and relieve system pressure completely to prevent injury or seal damage. Clean the seating groove of debris, old seal material, and residual lubricant before installing the new ring. Apply a compatible O-ring lubricant to the seal and groove surfaces to ease installation and reduce the risk of twisting or pinching the cross-section.