Aim at lacking a kind of method for drawing intersecting lines efficiently in the petrochemical engineering construction, invented a kind of compasses that can draw the opening curve on the non-flat container wall.

• 摘要针对石油化工设备建造中，缺乏一种高效的器壁开孔画曲线方法的问题，研制了一种能在非平面器壁上画开孔曲线的画线规。