3/8" x 1/2" x 164' Insulation Line Set

Mueller Duraguard Line Set – 3/8" x 1/2" x 164' UV-Resistant Insulated Copper Tubing

The Mueller 00621640C Duraguard line set includes two copper refrigerant lines—3/8" liquid and 1/2" suction—encased in UV-resistant insulation and factory-paired for efficient installation. Designed for HVAC systems requiring long line runs, this 164-foot set is constructed to withstand exposure to outdoor conditions while maintaining thermal and mechanical integrity.

The Duraguard jacket system features a co-extruded polymeric outer layer that shields the insulation from ultraviolet degradation and mechanical wear. It is engineered for use in residential and light commercial HVAC installations and conforms to ASTM B1003 for factory-fabricated line set performance.

Key Performance Features

• UV-Resistant Outer Jacket – Protects against prolonged sun exposure without degrading insulation integrity.
• Pre-Insulated Copper Tubing – Reduces onsite labor and material handling by providing a fully fabricated solution.
• Pressure Rated to 700 PSI – Suitable for high-pressure R-410A and other modern refrigerants.
• ASTM B1003 Compliant – Meets industry standards for preassembled refrigerant line sets.
• 10-Year Manufacturer Warranty – Backed by long-term product assurance from Mueller Industries.

Technical Specifications

• Line Set Length: 164 feet
• Liquid Line: 3/8" O.D. copper
• Suction Line: 1/2" O.D. copper
• Insulation: Closed-cell with UV-resistant polymeric jacket
• Maximum Operating Pressure: 700 PSI
• Standards: ASTM B1003
• Origin: Manufactured in the USA

Installation Considerations

This product is intended for use by qualified HVAC professionals. Proper installation requires appropriate flaring, brazing, and system evacuation tools. The self-contained jacket minimizes field wrapping requirements, but sealing terminations and connections is essential for maintaining vapor barrier continuity and system efficiency.

Application Guidance

The Mueller Duraguard line set is suitable for use in split-system heat pumps, air conditioners, and mini-split systems requiring long-distance refrigerant connections. Its durable outer jacket and performance-tested insulation make it a reliable solution for rooftop, wall-mount, and exposed exterior routing scenarios.