The tubes of waterwall, superheater, reheater and economizer are the main boiler heating surface, whose secure and stable operation relate directly to the security of the whole power plant.

• 水冷壁管、过热器管、再热器管、省煤器管(“四管”)是锅炉内部的主要受热面，它们能否安全稳定地运行直接关系到整个电厂的安危。