進口球閥的發明及應用歷史
進口球閥問世于20世紀50年代，隨著科學技術的飛速發展，生產工藝及產品結構的不斷改進，在短短的40年時間里，已迅速發展成為一種主要的閥類。在西方工業發達的國家，球閥的使用正在逐年不斷的上升，在我國，球閥被廣泛的應用在石油煉制、長輸管線、化工、造紙、制藥、水利、電力、市政、鋼鐵等行業，在國民經濟中占有舉足輕重的地位。球閥是由旋塞閥演變而來。它具有相同的旋轉90度提動作，不同的是旋塞體是球體，有圓形通孔或通道通過其軸線。球面和通道口的比例應該是這樣的，即當球旋轉90度時，在進、出口處應全部呈現球面，從而截斷流動。主要的球閥細分有： 進口高壓球閥，進口美標球閥，進口日標球閥，進口保溫球閥，進口三通球閥，進口電動球閥，進口氣動球閥，進口不銹鋼球閥，進口螺紋球閥，進口全焊接球閥，進口兩片式球閥，進口三片式球閥，進口渦輪全焊接球閥，進口高壓小型球閥，進口高壓焊接球閥。
Ball valves start another technology climax The ball valve introduced in the 1950s, with the rapid development of science and technology, production processes and product mix of continuous improvement in a short span of 40 years, has quickly developed into a main valve. In Western industrialized countries, the use of the ball valve is year by year continually rising in China, the ball has been widely used in petroleum refining, the long pipeline, chemical, paper, pharmaceutical, water, electricity, municipal, iron and steel industry occupies a pivotal position in the national economy. The ball valve is evolved from the stopcock. It has the same action, rotate 90 degrees to mention is the cock body is a sphere, a circular through-hole or channel through its axis. Sphere and the ratio should be such, that is when the ball spins 90 degrees, into the exit should be fully rendered sphere, thus cutting off the flow.