Insulated copper coil , include copper pancake coil tube , c12200 copper tube, pure copper round tube which is most often used for supply of hot and cold tap water, and as refrigerant line in HVAC systems. Our copper tube has a feature of clean surface,bright finish,even structure,high precision size,welding easily, good shaping.The executive standard of the pancake coil is GB/T17791-2007,ASTMB280,JIS H3300.The executive standard of straight copper pipe is GB/T 17791-2007,ASTM B280,JIS H3300,ASTMB88.Welding point: no pores,cracks,slag,burrs and burn,not fusion,no obvious oxide film,no plug hole without significantly reduced(Φ6.3hole is larger than 3.0mm);Air tightness: using a high pressure for 4.0MPa pressure for 5 minutes, no leakage; Pressure: after the air tightness check is qualified, slowly press the pressure to 13MPa,keep for 1 minute, without any cracks ;Bending: The sample is bent into a curved core diameter of 2 times than the nominal diameter of the pi…