“When space is a limiting factor, the liquid has fibrous substance that can get lodged in the bottom cavity of a valve body, the hydraulic heads moderate, a Knife Gate Valve can do the job admirably.  However, exercise caution when choosing a knife gate valve over the time tested Gate Valve”

The minimum stress point in a knife gate valve is somewhere near the major axis between the two vulnarable section probably where the short and long side join. therefore provide as large a fillet radius as posible as stress here appreciably increses with diminishing radius. A square cornered chest would induce abnornally high stress . the reason why all pressure vessels are rounded with no sharp corner