刀闸阀用作“忍者”，挥动刀片以切断管道中的重型液体的堵塞。搭配锋利的刀片，通常存在于大多数腐蚀性，侵蚀性和磨料的情况下，纸浆和造纸工业是刀闸阀最初设计的一种情况。在过去，粘性纸浆将被夹在普通闸阀的楔形和座椅之间，因此流动流不能关闭。刀闸阀在那里，具有锋利的切削刃，能够解决问题并切断纸浆并密封它。刀闸阀如何摆脱这种巧妙的特点，刀闸阀已经出现在运输粘性液体，浆料和其他东西的地方时更加流行。如今，刀闸阀用于许多加工厂，尺寸较大，这使得更容易处理轻油，重油，清漆，泥浆，废水和纸浆等密集流体。应该注意的是，这些阀门具有低压限制，并且在刀片切割其处理的材料之后，刀片将返回弹性体密封件。厚的液体可以平滑地滑过这些柔软的密封件，但是，当固体物质或粉末穿过刀闸时，这些粗糙物质最终将在刀闸末端的软密封中积聚。发生这种情况时，这些阀门的密封性能将会衰落。如果发生这种情况，则需要更换密封。 When not to Use Knife Gate Valves Knife gate valves can not be used to regulate the flow stream, because vibration occurs when the fluid is forced to flow through a partially closed gate valve and erodes the wedge and seat. Therefore, the knife gate valve can be used only when it is completely closed or opened.

不同的阀门适用于不同的条件。如果你认为阀门只是一个简单的开关，可以像水龙头一样切断流量的简单开关（尽管龙头实际上是一个阀门）。但是，请进一步探索阀门的工作以及如何为特定目的选择右阀门！用于切断流动的阀门直通阀，具有相对较小的流动阻力，通常用于切断流量。在触点，具有曲折路径的球墨阀和柱塞阀等下的闭合阀具有比其他阀门更高的流动性。因此，这种阀门用于控制允许高流动阻力的流动。用于流量控制的阀门通常我们选择容易调节流量作为流量控制的阀门。上面提到的下闭阀在这种情况下工作，因为其座椅尺寸与楔形的行程成比例。旋转阀（塞阀，蝶阀，球阀），夹阀和隔膜阀也可用于控制流动。但它们仅在有限的阀门直径范围内施加。 The gate valve uses a disc-shaped gate to make a transverse movement to the circular valve seat. It can control the flow rate only when it is about to close, so it cannot be used for flow control. Valve used to reverse and divert the flow In accordance with the need of reversing and diverting, this kind of valve has three or more channels. Plug valves and ball valves are more suitable for this. However, in some cases, other types of valves can also be used for reversing and diverting as long as two or more valves are properly connected to each other. Valve used for medium with particles Speak of transferring medium with floating particles in it, the best choice is to choose the valve whose disc slides along the sealing surface. The disc will wipe this area while it moves. If the disc moves vertically along the seat ring, particles may be stuck at the sealing part. Ball valve and plug valve will clean its sealing surface when they are working, hence, they can be put in particle-mixed medium transportation. At present, no matter in the pipeline system of petroleum, chemical industry, or in other industries, the application, operation frequency and service of the valve are ever-changing. To control or eliminate even the smallest leakage, the most important and critical equipment is the valve. The ultimate control of the pipeline is the valve, which plays a unique and reliable role in various fields.

众所周知，这种工作于-40℃~ -196℃介质的阀门称为“低温阀门”。低温阀门，包括低温应急关闭阀、低温球阀、低温闸阀、LNG低温阀门、NG低温阀门等，通常在30万吨乙烯项目和液化天然气生产等化工厂中使用。低温阀输送的乙烯、液氧、液氢、液化天然气、液化石油等液体介质易燃易爆。更重要的是，当温度上升时，它们会气化并膨胀数百倍。这种阀门总是配备加长阀帽或即加长阀杆。这是因为:1。加长阀盖可以防止在低温阀门和其他阀门中起重要作用的填料函因低温而损坏。随着温度的下降，填料的弹性会逐渐减弱，失去防止泄漏的能力。然后，介质冻结在填料和阀杆之间的空间，阻碍阀杆的移动，并在阀杆移动时刮伤填料。最终，随之而来的是严重的泄漏。 Therefore，a extended stem is used to ensure that the packing is warm enough, at least above 8 ℃. 2. The extended structure of bonnet makes it convenient to wrap special materials around the valve, preventing the loss of cold energy. 3. The pipes and valves are often installed in the so-called 'cold box', but its ‘long neck’ can go through the wall of the 'cold box'. Based on that, The extended stem makes it convenient to dismantle or replace the main parts of the valve quickly through the bonnet. Hence，the valve body and the pipeline are welded together to reduce the leakage of the cold box as much as possible and ensure the sealing performance of the valve.

随着电磁阀使用量的增加，电磁阀的前景越来越好。今天，我们将讨论为什么它变得越来越受欢迎。首先，环保和可持续发展政策在工业上的引入，产生了节能理念，这与电磁阀的发展标准是一致的，即节约水、能源、材料等资源。其次，电磁阀的设计消耗更少的能量，减少了由于流动阻力造成的能量损失。这是阀门行业的发展方向。因此，电气设备在节能工业中得到了广泛的应用。您可以通过升级其结构和选择低功耗、低噪音的装置来减少能耗。在上述两个原因的前提下，我们应该投入更多的精力和资金在电磁阀的研究、创新和开发上，使其在高新技术产业中发挥巨大的作用。

铸造法在阀门工业中应用广泛。本文将讨论铸钢阀门的优缺点。优点1。铸钢阀门由液态金属制成，因此在尺寸和形状上更灵活，即使形状复杂。2.在材料及其化学组成方面有很大的差异。因此，合金钢阀门通常采用铸造方法制造。3.不那么复杂和昂贵的过程导致了它的广泛可用性。4. Cast steel valves have a contoured shape with round edges. This makes them easy to install even in small spaces and pipelines. Demerit 1. Some material is lost when melting. The liquid is then reworked as it is put into and removed from molds. The overall process will generate lots of material waste. 2. There can be some impurities like cracks and voids during its solidifying process. This will lead to a lower mechanical property. 3. The heat treatments can alter the micro-structure of the castings after welding. This results in higher creep and lower hardness of the valve. Rigorous inspection is required to make sure the valve has retained its strength and creep resistance after being welded.

旋塞阀是一种比较老的阀型，包括套筒式旋塞阀、润滑式旋塞阀和多路式旋塞阀。它依靠塞体绕阀体中心线旋转，达到开启和关闭的目的。旋塞阀的作用一般用于切断、分配和改变介质流动方向。该旋塞阀结构简单;外形尺寸小;在操作过程中只需要90%的流体阻力。适用范围广，特别适用于低压、小直径、介质温度等场合。旋塞阀的缺点是开关费力，密封面容易磨损，高温高压下容易卡死，不适合调节流量。球阀是由旋塞阀演变而来的。它的开闭部件是一个球。 The ball is rotated 90 degrees around the axis of the valve stem to achieve the purpose of opening and closing. It is mainly used to cut, distribute and change the flow of the medium Orientation, the ball valve designed as a V-shaped opening also has a good flow adjustment function. When used for shut-off, the plug valve has a slightly better adjustment capacity than the ball valve, but has limited advantages. Although the plug valve has a sealing surface much larger than the ball valve, the sealing effect is good, but it also brings the disadvantage of too much torque and insufficient flexibility. Due to the influence of the weight of the cock, the conventional positive cock structure is difficult to achieve a large caliber. If you want to use a large-size valve, you must use an inverted cock structure, that is, the cock has its head pointing down. This inevitably reduces the sealing effect under the action of gravity. It has to be sealed by grease injection. It is used for storage and transportation of natural gas and oil, but cannot be used in other industries, because grease will contaminate the medium. Although the ball valve's sealing effect is slightly poor in theory, it can be made into a large caliber. With the improvement of processing accuracy and sealing material, the ball valve's sealing effect can already meet the actual application requirements, and the application range is wider. When used for adjustment, there is not much difference between the two, and appropriate holes can be made in the rotating body for adjustment. Therefore, the general plug valve is used in occasions with higher sealing requirements, but the diameter is generally smaller, and the ball valve can be applied to more and more extensive industrial occasions.