閥門的泄露在生活以及工業生產中十分普遍,且帶來的影響非常大,輕則會造成浪費,或給生活帶來危險,如自來水閥門泄露,重則導致嚴重后果的發生,如化工行業的有毒、有害、易燃、易爆及腐蝕性介性質的泄漏等,嚴重的威脅人身安全、財產安全和環境污染的事故。一臺依靠外力旋轉傳動開及關閉的閥門,都設計有一個密封裝置,既用在填料涵中裝上一定數量的填料密封圈,以至達到密封效果,但密封情況有如何呢?閥門的填料處泄漏,是閥門中非常容易出現泄漏故障的部位其一,但究其原因大為以下各個方面的原因。
The leakage of valves is very common in life and industrial production, and the impact is very large. At least, it will cause waste or bring danger to life. For example, the leakage of tap water valves will lead to serious consequences, such as toxic, harmful, flammable, explosive and corrosive dielectric leakage in the chemical industry, which will seriously threaten personal safety, property safety and environmental pollution. A valve that depends on external force to rotate and drive to open and close is designed with a sealing device, which is used to install a certain number of packing sealing rings in the packing culvert to achieve the sealing effect, but how about the sealing condition? The leakage at the packing of the valve is one of the parts of the valve that are very prone to leakage faults, but the reasons are mainly due to the following aspects.
1、密封副結構;在溫度或密封力作用的變化下,密封副的結構就會發生變化。而且這種變化會影響和改變密封副相互之間的作用力,從而使閥門密封的性能減小。因此,在選擇密封件時,一定要選擇具有彈性變形的密封件。同時,也要注意密封面的寬度。原因在于密封副的接觸面不能完全吻合,當密封面寬度增加,就要加大密封所需要的作用力。
1. Sealing auxiliary structure; Under the change of temperature or sealing force, the structure of the sealing pair will change. Moreover, this change will affect and change the force between the sealing pairs, thus reducing the performance of the valve seal. Therefore, when selecting seals, we must choose seals with elastic deformation. At the same time, pay attention to the width of the sealing surface. The reason is that the contact surface of the sealing pair cannot match completely. When the width of the sealing surface increases, it is necessary to increase the force required for sealing.
2、密封面比壓;
2. Specific pressure of sealing surface;
密封面的比壓大小影響著閥門密封性能大小和閥門的使用壽命。因此,密封面比壓也是非常重要的一個因素。在相同的條件下,比壓太大會引起閥門的損壞,但比壓太小酒會造成閥門泄漏。因此,需要我們在設要充分考慮到比壓的合適度。
The specific pressure of the sealing surface affects the sealing performance and service life of the valve. Therefore, the specific pressure of the sealing surface is also a very important factor. Under the same conditions, the valve will be damaged if the specific pressure is too high, but the valve will leak if the specific pressure is too low. Therefore, we need to fully consider the suitability of specific pressure in design.
3、介質的物理性質;介質的物理性質也影響到閥門密封性能。這些物理性質包括溫度,粘度和表面的親水性等。溫度變化不僅影響著密封副的松弛度和零件尺寸的改變,還與氣體的粘度有著密不可分的關系。氣體粘度隨著溫度的升高或降低而增大或減小。因此,為了減少溫度對閥門密封性能的影響程度,我們在進行密封副設,要把其設計成彈性閥座等具有熱補償性的閥門。粘度與流體的滲透能力有關。當在相同條件下時,粘度越大,流體的滲透能力就越小。表面的親水性是指在金屬表面有一層薄膜時,要去掉這層薄膜。因為這層很薄的油膜,會破壞表面的親水性,導致堵塞流體的通道。
3. Physical properties of the medium; The physical properties of the medium also affect the sealing performance of the valve. These physical properties include temperature, viscosity and surface hydrophilicity. The temperature change not only affects the relaxation of the sealing pair and the change of the part size, but also has an inseparable relationship with the gas viscosity. The gas viscosity increases or decreases with the increase or decrease of temperature. Therefore, in order to reduce the influence of temperature on the sealing performance of the valve, when we design the sealing pair, we should design it as a valve with thermal compensation such as elastic valve seat. The viscosity is related to the permeability of the fluid. Under the same conditions, the greater the viscosity, the smaller the permeability of the fluid. Surface hydrophilicity refers to the removal of a thin film on the metal surface. Because this thin oil film will destroy the hydrophilicity of the surface, resulting in blocking the channel of the fluid.
4、密封副的質量;密封副質量主要是指我們要對材料的選擇,匹配,制造精度上進行把關。比如,閥瓣與閥座密封面很吻合,能提高密封性。環向波紋度多的特點,是其迷宮密封性能好。
4. Quality of sealing pair; The quality of sealing pair mainly refers to the selection, matching and manufacturing accuracy of materials. For example, the sealing surface of valve clack and valve seat is very consistent, which can improve the sealing performance. Its labyrinth sealing performance is good because of its high circumferential waviness.
The above is a detailed introduction of Lianggong valve agent, which I hope will help you. If you have any questions, please contact us. We will provide services for you with a professional attitude http://m.design021.cn