Although pressure head of gravity action is smaller than hot water recycle pump, it is one important cause of leading to vertical imbalance of double pipe heating system.
相对于热水循环泵的作用压头,尽管重力作用压头很小,但它是引起双管采暖系统垂直失调的重要原因,在设计分户热计量采暖系统时,必须充分重视其不利影响。
The research and application of the metal mold vacuum gravity exactitude foundry method on aluminum alloy;
金属型真空重力精密铸造技术的研究及在铝硅系合金铸造上的应用
