Bluestar International supplies Cross type Union Tube Fitting. Bluestar International is an ISO 9001: 2000 and ISO 14001:2004 recognised company manufacturing a wide range of instrumentation tube fittings, valve fittings, flanges and piping products. The Cross type Union Tube Fitting comes in various tube diameter sizes ranging from 1/8 inch to 1 inch and is available in different specifications to suit application in instrumentation and process control system tubing, double ferrule compression tube fittings and tubing lines.