Recently, Yingli group proposed: through the product technology upgrades, improve the quality requirements of cast iron valve. Cast iron valves have many advantages in the application, for example, fluid resistance is small; open and close save more effort; media flows unrestricted, Not disturbing flow, not reduce the pressure; simple shape, good manufacturing processes, wide application scope.

But also exist these shortcomings: easy to cause erosion and abrasion between the sealing surface, difficult to repair; open need space, opening and closing need a long time; structure is more complex. Therefore, Yingli group hope that through technology upgrading and improvement, takes its essence, discarding the dross, make cast iron valves market share continuously improve.