The Mueller Streamline® 61420500C is a 50-foot standard refrigerant line set combining a 3/8" liquid line and 7/8" suction line, insulated with 1/2"-thick Duraguard UV™ coated elastomeric foam and finished in a weather-resistant black oxide polymeric jacket. Built from UNS C12200 phosphorus-deoxidized copper to ASTM B280, nitrogen-charged, UL Recognized to 700 PSI, and ASTM B1003-compliant, this domestically manufactured line set handles R-410A, R-32, and next-generation HFC refrigerant circuits in 2- to 5-ton split-system air conditioner and heat pump installations — including exposed outdoor and rooftop runs where standard elastomeric insulation fails. What the "C" Suffix Actually Means — 61420500 vs. 61420500C, & Why the Distinction Matters Before You Order Buyers searching for the Mueller Streamline® 61420500 and the 61420500C are looking at two meaningfully different products — one carries standard black elastomeric foam insulation, the other carries the Duraguard UV™ coated elastomeric system. The base model, 61420500, wraps its 7/8" suction line in conventional closed-cell elastomeric foam with no UV-protective outer barrier. That insulation absorbs solar radiation directly, begins surface degradation within 12 to 18 months of outdoor exposure, and carries no manufacturer warranty for UV resistance because the material was never designed to withstand prolonged direct sunlight. The 61420500C replaces that bare foam with Duraguard UV™ — a two-layer system where the inner elastomeric foam core retains the thermal resistance, and an outer polymeric jacket (responsible for the product's distinctive black oxide finish) blocks ultraviolet radiation before it reaches the foam beneath. That "C" designation is Mueller Streamline®'s code for this coated elastomeric specification, and it activates the separate 5-year limited UV resistance warranty that does not exist on the standard model. For interior-only installations — attic air handlers with fully enclosed line set runs — the standard model is adequate. Any installation where the refrigerant lines exit the building envelope and run even a short distance in ambient weather warrants the 61420500C specifically. UNS C12200 Phosphorus-Deoxidized Copper, O60 Annealed Temper & DuraGrain™ — The Metallurgy Behind This Line Set's Field Performance The tubing in the 61420500C is drawn from UNS C12200 phosphorus-deoxidized copper, produced at Mueller Industries' domestic facility using the company's proprietary DuraGrain™ grain-refinement process — a manufacturing distinction that directly affects how this line set behaves in the field. Phosphorus deoxidation removes dissolved oxygen from the copper melt during the casting stage. That matters specifically during brazing: when a torch is applied to standard electrolytic tough pitch copper containing residual oxygen, the oxygen reacts with hydrogen in the flame atmosphere to form steam bubbles within the grain boundaries — a failure mechanism called hydrogen embrittlement. The phosphorus-deoxidized UNS C12200 alloy in the 61420500C eliminates this reaction, allowing silver brazing alloy (BCuP-5 or equivalent AWS A5.8 classifications) to flow cleanly into joints without grain boundary damage. The tubing is manufactured in O60 annealed temper. Annealed copper carries a yield strength of approximately 5,100 PSI — substantially lower than hard-drawn tube — which allows field technicians to hand-bend the line set through 90° routing changes without kinking, using a standard ACR spring bender or lever-type
Visit Product Page
