该系列调与 210C 的不同之处为：采用阀杆贯通流路，顶底双填料密封方式。这样一方面可相互抵消流体对阀杆的推力，适用于高压场合；另一方面可消除阀杆热膨胀的影响，适用于高温场合；另外，该系列的部分球面形阀板不设有 V 形切口。

This series is same as 210C series except that the stem penetrates the body and is supported by double gland packing. The stem's blow out force is set off in this construction making it suitable to heavier services such as high pressure, high temperature service because of heat expansion insulation design stem.