常見例句雙語例句First: to act as an automatic non-return valve by preventing a backflow of steam from the main steam header to the boiler.首先，能過作爲(wèi)一個自動逆止閥，防止蒸汽從主蒸汽加熱器上倒流到鍋爐裡。The design and principle of working in the invention steam from traditional oil pump. The main components, as cylinder plug, oil valve, oil clumber-controlled muff, are same with the traditional.該泵的設(shè)計和工作原理源於傳統(tǒng)油泵，主要部件如柱塞、油閥、油量控制套筒和傳統(tǒng)油泵相同。ip.com 返回 main steam valve