Use just enougn solder: with wire solder, use 3/4" for a 3/4" valve, etc. If too much solder is used, it may flow past tube stop and clog sealing area.
使用适量的焊料：如果使用线状焊料，那么对公称通径为3/4英寸的阀门就要采用3/4英寸的焊料，等等。
To make a proper brazing joint, the clearance between the solder cup and the tube should be approximately 0.001" to 0.010" (0.0254mm to 0.254mm).
焊料杯口和管道之间的间隙应该大致在0.0254毫米至0.254毫米之间，才能够获得正确的铜焊连接效果。
应用推荐