旋塞阀结构简单，启闭快，流体阻力小，是应用最早的阀门之一。普通旋塞阀是通过成品金属塞体与阀体直接接触进行密封，具有密封性差、启闭力大、易磨损等缺点。它们只能用于低(不高于1mpa)和小直径(小于100mm)的场合。为了扩大旋塞阀的应用范围，人们开发了许多新的结构。油封旋塞阀是最重要的一种。从阀体锥度孔与塞体之间的塞体顶部注入特殊润滑脂，形成油膜，减小启闭扭矩，提高密封性能和使用寿命。其工作压力可达64mpa，最高工作温度可达325℃，最大直径可达600mm。旋塞阀的关闭部分是一个带孔的圆柱，它围绕垂直于通道的轴线旋转，从而开启和关闭通道。旋塞阀的优点:便于频繁操作，启闭快捷; 2. Low fluid resistance; 3. Simple structure, relatively small volume, light weight and easy maintenance; 4. Good sealing performance; 5. The installation direction is unrestricted, the flow direction of media can be arbitrary; 6. No vibration and low noise. Classification of plug valves: 1. By structure: tight set plug valve, self-sealing plug valve, pressure balance plug valve and oil seal plug valve; 2. By channel: straight plug valve, three-way plug valve and four-way plug valve. The channel of plug valve has many forms. The common straight through type is mainly used to cut off the fluid; Three-way and four-way plug valve are suitable for fluid reversing.

平闸阀是一种滑动阀，其关闭部分为平行闸板。闭合部分可以是单闸板或双闸板，在它们之间有支撑机构。楔板对阀座的压紧力是由作用在浮动楔板或浮动阀座上的介质压力控制的。如果是双楔平闸阀，两个楔之间的支撑机构可以补充这种压紧力。平板闸阀的特点:阀座采用o形圈密封和带预紧力的浮动阀座结构，使平闸阀的进、出口双向密封。启闭扭矩仅为普通阀门的1/2;2.全开时，通道平直，流阻系数很小，没有压力损失，清洗简单;3. The packing structure with self sealing ability is adopted, the sealing performance is more reliable than ordinary graphite packing. In addition, grease is injected into the sealing surface of the packing, the sealing surface meets the zero leakage standard; 4. When the flat gate valve is closed, it can automatically remove the high pressure in the inner cavity to ensure the safety of use; 5. Fully enclosed structure, good protection performance. Flat gate valve is divided into single gate plate and double gate plate. According to the connection mode, it can be divided into butt welded flat gate valve and flange flat gate valve. Features of butt welded flat gate valve: 1. Small fluid resistance and small scouring and erosion of sealing surface by medium; 2. Opening and closing is labor-saving; 3. The flow direction of the medium is unrestricted, no turbulence and no pressure reduction. 4. Simple shape, short structure length, good manufacturing technology and wide application range. Flange flat gate valve is stable and reliable when used in pipeline, Therefore, DERVOS recommends that flange flat gate valve could be used in high pressure pipeline. Features of flange type flat gate valve: 1. The sealing structure of flange flat gate valve is elastic with preload, and the upstream and downstream sealing seats are sealed at the same time. There is always face-to-face seal between the valve seat and the seal; 2. The valve seat has self-cleaning function and is not directly scoured by the air flow during the opening or closing of the valve. The valve seat is made of lubricated and non abrasive materials; 3. The problem of the valve actuator will not affect other parts of the valve, and the maintenance and replacement can be carried out without removing the valve; 4. When the flange flat gate valve is fully opened, the channel is smooth and straight, the flow resistance coefficient is very small, there is no pressure loss, and the pipeline can be cleaned by wool ball.

2022年是中国的虎年。它让人们期望他们可以像老虎一样勇敢和强壮，继续努力工作。DERVOS 2021年年会在春节假期后的第二个工作日(2月14日情人节)召开。上午，各部门负责人进行了工作汇报。在工作报告中，他们回顾了过去一年的工作成果。同时，制定了该部新的一年的工作目标和工作计划。最后，总经理Eric总结并规划了2022年的奋斗方向。关键词是务实和发展。务实，就是扎实工作，减少试错成本，用切实可行的方案开展工作。同时，从复杂到简单，以结果为导向，最终目标是实现发展。晚上，年度工作总结落下帷幕，年度晚宴正式开始。这不仅是不同部门聚在一起的好时机，也是赢得大奖的好机会。 DERVOS people work hard and also love life. We are grateful to the support of our business partners over the past year. We will continue to improve and provide partners with the most professional support and meticulous service.