Full-opening through conduit gate valves are designed to satisfy the long distance transportation service of crude oil and natural gas. It is designed in accordance with API6D with DBB function, thus valve can offer bi-directional on- off services. Neway developed 2 two series of full-opening through conduit gate valves: soft seated with slab gate series and metal seated with expanded gates series. The maximum working temperature can be up to 500℃.