⊙高性能蝶閥（對夾式）High performance butterfly valve （Wafe）
一般的高性能蝶閥為單偏心或雙偏心結構。雙偏心結構是在設計時將閥軸偏離密封面中心線，軸稍稍離管路中心線，形成第二偏心，偏心的目的在于使蝶板開至大約20°之后，閥座與密封圈之間脫離，從而減少摩擦。
Generally，high performance butterfly valves are sing le eccentric or double eccentric，As to double eccentric structure，valve shaft is designed deviated from the centerline of sealing face to form up the first eccentric，and slightly deviated from the centerline of pipe to form up the second eccentric，the eccentrics are to make seat disengaged from sealing ring to lower the friction when disc is opened to approximay20°.
軟密封閥座選用丁「E、尸丁「三、R丁F氫薪火結構符合“尸1607的火鍬驗， 在發(fā)生災時具有密封能力。
硬密共精構具有本質的防火能力，可保持雙向無泄漏?？稍诓徊鸬濉㈤y桿的情況下更換閥座，上下閥桿處沒有低摩擦系數(shù)的軸套，減少了閥門啟閉時閥桿的摩擦力。
雙偏心的設計結構，減小了開啟頻繁時密封副上下兩端的磨損。閥門與驅動裝置接口符合ISO5211，產品質量嚴格按I S05211進行控制。
Soft Seal Seat， made of TFE, PTFE or RTFE, fireproof constr一uction conforming to AP1607 fire test, provided with sealing Property in case of fire.
Hard seal structure is provided with intrinsical fireproof property. Two way leak一proof seal. Seat replaced with no need to take off disc and stem the upper and lower stems provided with low friction sleeves to lower the frictional force of stem when valve is opened or closed.
Double eccentric structure to lower the abrasion at the upper and lower ends of seal in case of frequent open and close. The interface between valve and drive unit conforms to ISO5211.Product qua一lity is under rigorous control according to ISO9001.
⊙閥座密封原理 Principle of Seat Sealing
1、 蝶板處于關閉狀態(tài)，介質從閥座上游進入，在介質力的作用下，密封圈緊貼蝶板密封面，由于密封圈的彈性和變形作用，保證密封副的密封。
2、 蝶板處于關閉狀態(tài)，介質由閥座下游進入，在壓板上擠壓下，密封圈克服介質的作用力，緊貼蝶板密封面，焦證密封副的密封。
1. Disc closed, medium enters from the upstream of seat. Under the force of medium, sealing ring will get close to the sealing face of disc, and the elasticity and deformation of sealing ring will function to guarantee the performance.
2. Disc closed, medium enters from the downstream of seat. Under the extrusion of press board ring sealing will overcome the acting force of medium and get close to the sealing face of disc, thus to guarantee the sealing performance.
