1.Design to API 6D, 2.Fire tested to API 607, 3.Soft or metal to metal sealing, 4 ... low temperature, sulphur-resistant and non-sulphur- resistant valve by valve type.2,All the valves have suitable design structure ... and advanced military manufacturing technique. 3,Valve teat is so strict that each valve is tested, measured,and the results ... time and provide the considerate service. Steel Ball Valve