Duro-Line

Duro-Line is a line of USA-made steel refrigerant line sets manufactured by Duro Dyne Corporation, founded in 1952 in New York as a manufacturer of HVAC sheet metal accessories. Duro-Line was introduced as a domestic alternative to copper line sets, addressing supply chain vulnerability and copper price volatility. The tubing carries a 20-year limited warranty; insulation carries a 5-year limited warranty.

Product Lines

• Material: Coated low-carbon steel; higher strength and corrosion resistance vs. copper
• Sizes: 1/4", 5/16", 3/8", 1/2", 5/8", 3/4", 7/8" OD
• Lengths: 15', 25', 35', 50' pre-fab; 164' bulk coils in all diameters
• Configurations: Insulated and uninsulated
• Pressure: 5,500 psi continuous operating; burst strength over 7,000 psi; ~40% higher than copper
• Temperature: -55°F to 500°F operating range
• Refrigerant approval: A1, A2L, A3 refrigerants; R-410A, R-454B, R-32, R-290, R-600a and all current HVAC refrigerants
• Origin: Made in the USA

Why Contractors Specify Duro-Line

• Stable cost vs. copper: eliminates commodity price volatility in line set procurement
• Domestic supply chain: USA manufactured, not subject to copper import disruptions
• 40% higher operating pressure vs. copper provides safety margin for high-pressure refrigerants
• A2L and A3 refrigerant approval covers current and next-generation low-GWP equipment
• 20-year tubing warranty exceeds typical copper line set warranty terms

How to Choose Duro-Line Line Sets

Select diameter per the equipment manufacturer's line set specification (same OD sizing as copper). Pre-fab lengths: 15', 25', 35', or 50'. Bulk coil: 164' for custom runs. Insulated for exposed/unconditioned spaces. Confirm refrigerant type (including A2L) for the installed equipment; Duro-Line is approved for all current refrigerant classes.

Frequently Asked Questions

• What material? Coated low-carbon steel for higher strength and corrosion resistance vs. copper.
• Compatible with A2L refrigerants? Yes. Approved for A1, A2L, and A3 refrigerants including R-454B and R-32.
• Strength vs. copper? ~40% higher operating pressure; 5,500 psi continuous; burst strength over 7,000 psi.
• Warranty? 20-year limited on tubing; 5-year limited on insulation.
• Who makes it? Duro Dyne Corporation, founded 1952 in New York; US HVAC manufacturer since 1952.