Threaded union 1, Ex-mark: ExdII protection: IP55 corrosion rating: WF1 2, made of carbon steel, zinc plated or stainless steel, 3, thread size can be special, such as the NPT, metric thread and so on. Quality assurance: the date when product quality problems one year warranty, three-year replacement of the product purchase. Ex union Ordering Information: label should indicate the internal and external screw thread size, such as CBHJ-G3 / 4 "(inside) / G1" (outer) side of the meaning external thread G1 "in line with GB3836-2000, IEC60079 standard request. threaded union