1.Design to API 6D, 2.Fire tested to API 607, 3.Soft or metal to ... metal sealing, 4.Self relieving seats, 5.DBB 1,Cast steel ball ... ball type, high, middle and low pressure, high, middle and low temperature, sulphur-resistant and non-sulphur- resistant valve by valve type.2,All ... the products in time and provide the considerate service. Steel Ball Valve