NV1 NitroVue Nitrogen Flow Indicator, gold/silver, 7.7 oz.

Uniweld's NV1 NitroVue Nitrogen Flow Indicator is nitrogen purging simplified. The easy to read flow indicator label and the precision adjustable valve give complete control over the low flow of nitrogen gas during the brazing of copper tubing in Air Conditioning and Refrigeration systems. 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. The nitrogen must be flowing to displace the oxygen inside the tubing during the brazing process, preventing internal oxidation and the resulting scale. Scale build up inside the tubing can cause blockage in the TXV and within the Air Conditioning and Refrigeration system resulting in premature failure. If the orange ball does not rise in the tube there is no flow of nitrogen, only static pressure and oxygen is not being displaced. The NV1 must be connected to a Nitrogen Regulator with the delivery pressure set at 60 psi to control the nitrogen gas pressure. The NV1 can be used with complete confidence because it is protected from over pressure with a reseatable safety blow off that opens at 200 psi.