Based on analyzing the gravity of the problem of the protective closure obstructive valve s swing and the towing force,a few schemes have been put forward in the paper.

• 针对防护密闭门在关闭门扇过程中存在的门扇重、牵引力大等问题进行了探讨,并提出了解决该种问题的方案,及对已经应用到实际工程中的复位机构方案进行了详细分析。