由济南市市中给水设备机械厂设计生产的《油压微阻缓闭止回阀》枝术研讨会于1993年4月12日～13日在济南市召开。省、市、区有关领导及城建系统、冶金矿山系统、化工系统的工程技术人员和产品用户等约170位代表出席了会议。与会代表听取了该厂刘达东总工程师所做的关于产品的技术、性能介绍及用户代表的发言。 By the Jinan City Water Supply Equipment Machinery Plant design and production of “hydraulic micro-resistance slow closure check valve” branch seminar on April 12, 1993 to 13 held in Jinan City. Approximately 170 delegates attended the conference, including leaders from related provinces, cities and districts, urban construction systems, metallurgical and mining systems, chemical engineering system technicians and product users. Participants listened to the speech made by chief engineer Liu Dadong on the technology, performance introduction and user representatives of the plant.