Which filler for copper-to-copper versus copper-to-brass joints?

Copper-to-copper is brazed with copper-phosphorus filler (CuP, e.g. 2% Ag) without flux — the phosphorus self-fluxes. Copper-to-brass or copper-to-steel joints require silver filler (typically 30–45% Ag) with the correct flux, because phosphorus makes the joint brittle on ferrous metals and brass.

Why braze under an OFN nitrogen purge?

Without nitrogen, the high temperature oxidises the inner pipe wall, forming black copper-oxide scale. Loose oxide circulates with the refrigerant and clogs capillaries, expansion valves (TXV/EEV) and filter-driers. A steady, gentle flow of dry OFN nitrogen (about 0.02–0.05 m³/h) displaces oxygen and gives a clean, bright internal joint.

MAPP/propane or oxy-acetylene for split and VRF systems?

For typical split diameters (6–16 mm) a MAPP or propane turbo torch is enough — lighter, cheaper to run and safer to transport. For heavier VRF lines, headers and condensing units that need fast, concentrated heat, an oxy-acetylene set with its higher flame temperature performs better.

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Palniki i lutowanie

Leak-free, permanent joints on copper pipe and capillary connections — torches and welders for brazing with silver and copper-phosphorus alloys.

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About this category: Palniki i lutowanie

Brazing torches (oxy-acetylene, propane/MAPP, and air-aspirated turbo types) produce a flame hot enough to braze copper with silver and CuP filler rods. This is the core tool for assembling refrigerant pipework: joining liquid and suction lines, brazing in valves, filter-driers, and connections. Welders and the supporting kit (regulators, hoses, igniters, flaring tools, benders) make up a complete set for running copper tube from cutting, through flaring of flare connections, to final brazing under an OFN nitrogen purge.

A pro selects the torch by fuel type and required temperature: MAPP/propane for diameters up to roughly 22 mm, oxy-acetylene for heavier sections and fast heating without excess oxidation. Flame control, weight and ergonomics for overhead work, cylinder availability and capacity, and tip compatibility all matter. When brazing refrigerant lines, always work under a flowing OFN nitrogen purge to prevent internal oxide scale that clogs expansion valves and filter-driers.

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