Abstract: The problems of common suspendedstart check valve existing in water system were analyzed. The characteristics of novel multifunctional idlestroke coupling slopingseat check valve and its action in different conditions were summarized. Some problems needing attention and suggestions of idlestroke coupling check valve and oil pressure slow closure device in device adjustment and system operation were put forward. Based on the practical application effects, the key points in overhaul and adjustment of idlestroke coupling slopingseat check valve were summarized, and the necessity of their popularization was discussed.

Key words: idle-stroke coupling, oil pressure slow closure device, check valve, water hummer, damping