1.Preeminent performance of adjustment control 2.One piece body 3.Reliable seat sealing,soft seat or metal seat 4.V pattern ball material,WCB,CF8,CF8M,etc. 5.Sealing packing with TFE or RPPL,ensure that has reliable sealing and no outleakage under the middle and high temperature. 6.Completed with manual ,pneumatic driver(with positioner) and adjustable electric driver.