Uniweld NV1 Nitro Vue Flow Indicator with 1 4" Flare Fittings Single Gas Flowmeter, Regular, Silver sold2024 for containers of this type DURATECH 10 Inch Aviation for containers of this type of material Switch Body Size : 65 x 22mm 2 The bright orange float ball visually confirms the flow of nitrogen gas and allows the technician to first "Purge" the copper lines at 20+ SCFH and then reduce the flow to "Braze" at 3 5 SCFH during the brazing process thus conserving its consumption and reducing operating cost Scale build up inside the tubing can cause blockage in the TXV and within the Air Conditioning and Refrigeration system resulting in premature failure