Bulkhead three-piece union is designed to connect internal tubing to the outside through the equipment enclosure. And the anti-rotation sleeve has been added to prevent fitting from rotation. These fittings have Interchangeable internal and external threads for leak-free connection with flexible and rigid pipe connection system. Fittings are available in PP and PTFE materials, non-toxic, odourless, heat resistant, resistant to chemical corrosion and various organic substances. And fine pitch nut is available in PPS and PTFE materials.