Characteristics： 1、 Design and manufacture of product are according to American petroleum institute standard API608.API6D。 2、 Liquid resistance is very small。 3、 The speed of open is very quick。The valve only turn on 900 may finish open and close. 4、 Seat material use Teflon or R-teflon,low friction,credible seal and easy open and close. 5、 The movement of sphere on the middle of seat has wipe function so may be suitable for medium of suspend granule. 6、 Stem use back seal and hyperbatic structure which may prevent stem’s striking under the medium pressure. 7、 According to the need of consumer may design anti-static,fire-resistant and preventing wrong operation locked organ. 8、 Sphere has floatable ball and fixed ball according to need of strength of open and close, The seat of fixed ball ball valve is float depending on the pressure of medium to produce piston’s effect,realizing seal,reducing strength of open-close.