Why Are Gaskets' Designs Gradually Out of Sight?
Why Are Gaskets' Designs Gradually Out of Sight?
Gaskets have long been an indispensable auxiliary tool for engineers in fastening operations. Their main responsibility is to protect the surface of the joint during the tightening process and prevent crushing and damage caused by direct contact. They also distribute the load reasonably under the bolt head and nut to ensure the uniformity and stability of tightening. However, with the advancement of technology and the development of engineering practice, gaskets are gradually being replaced by flange bolts in certain applications. Today, let's delve deeper into the reasons behind this transformation.
Firstly, we need to clarify that using torque to indirectly control the clamping force of bolts is currently the most commonly used method in engineering practice. This method is simple and easy to implement. It is well-known among engineers. However, in practical operation, it is not difficult to find that the friction acting on the bolt threads and under the bolt head will consume most of the tightening torque. This means that despite applying a large amount of torque, the part that truly translates into effective clamping force is actually quite limited.
In this context, the problems caused by gaskets are particularly prominent. Due to the lower hardness of standard gaskets compared to bolts and nuts, they are prone to plastic deformation under high stress. This deformation not only causes the gasket itself to collapse, but may also affect the clamping force of the bolt, resulting in a loss of clamping force. In contrast, flange bolts do not have this issue. Its supporting surface maintains the same overall hardness as the fasteners. It can maintain stable shape and performance under high stress.
In addition, the gap holes in the design of the gasket may also cause a series of problems. To avoid interference caused by the transition arc under the bolt head, the gasket needs to have a relatively large gap hole. However, this clearance hole may cause the center of the gasket to deviate from the bolt axis during the tightening process, resulting in eccentric loading and local stress concentration. This not only increases the risk of indentation and joint damage, but may also affect the stability and safety of the entire fastening system.
Another noteworthy issue is the phenomenon of the gasket following rotation. During the tightening process, sometimes the gasket will rotate along with the nut on the surface of the joint. This rotation will change the relationship between the applied torque and the bolt clamping force, resulting in a significant loss of clamping force. Unless carefully observed and monitored during the tightening process, it is difficult to detect and correct this issue in a timely manner.
Finally, the use of gaskets will also increase the number of contact surfaces inside the joint. At the microscopic level, the embedding phenomenon between these contact surfaces can lead to a loss of clamping force. Especially when the parts in the joint come into contact and are compressed for the first time, the embedding loss will be more significant. For the contact surface between metals, this loss is usually between 0.002 and 0.006mm. For painted surfaces, the embedding effect will be more pronounced. Therefore, the use of gaskets will exacerbate this effect and further reduce the clamping force of the bolts.
In summary, we can find that although gaskets play an important role in traditional fastening operations, their existing problems cannot be ignored. In contrast, flange bolts have higher stability, better reliability, and lower maintenance costs. Therefore, more and more engineers are choosing to use flange bolts instead of traditional gasket fasteners. Of course, during the replacement process, we also need to pay attention to adjusting the original installation torque to ensure the optimal tightening effect.
Gaskets have long been an indispensable auxiliary tool for engineers in fastening operations. Their main responsibility is to protect the surface of the joint during the tightening process and prevent crushing and damage caused by direct contact. They also distribute the load reasonably under the bolt head and nut to ensure the uniformity and stability of tightening. However, with the advancement of technology and the development of engineering practice, gaskets are gradually being replaced by flange bolts in certain applications. Today, let's delve deeper into the reasons behind this transformation.
Firstly, we need to clarify that using torque to indirectly control the clamping force of bolts is currently the most commonly used method in engineering practice. This method is simple and easy to implement. It is well-known among engineers. However, in practical operation, it is not difficult to find that the friction acting on the bolt threads and under the bolt head will consume most of the tightening torque. This means that despite applying a large amount of torque, the part that truly translates into effective clamping force is actually quite limited.
In this context, the problems caused by gaskets are particularly prominent. Due to the lower hardness of standard gaskets compared to bolts and nuts, they are prone to plastic deformation under high stress. This deformation not only causes the gasket itself to collapse, but may also affect the clamping force of the bolt, resulting in a loss of clamping force. In contrast, flange bolts do not have this issue. Its supporting surface maintains the same overall hardness as the fasteners. It can maintain stable shape and performance under high stress.
In addition, the gap holes in the design of the gasket may also cause a series of problems. To avoid interference caused by the transition arc under the bolt head, the gasket needs to have a relatively large gap hole. However, this clearance hole may cause the center of the gasket to deviate from the bolt axis during the tightening process, resulting in eccentric loading and local stress concentration. This not only increases the risk of indentation and joint damage, but may also affect the stability and safety of the entire fastening system.
Another noteworthy issue is the phenomenon of the gasket following rotation. During the tightening process, sometimes the gasket will rotate along with the nut on the surface of the joint. This rotation will change the relationship between the applied torque and the bolt clamping force, resulting in a significant loss of clamping force. Unless carefully observed and monitored during the tightening process, it is difficult to detect and correct this issue in a timely manner.
Finally, the use of gaskets will also increase the number of contact surfaces inside the joint. At the microscopic level, the embedding phenomenon between these contact surfaces can lead to a loss of clamping force. Especially when the parts in the joint come into contact and are compressed for the first time, the embedding loss will be more significant. For the contact surface between metals, this loss is usually between 0.002 and 0.006mm. For painted surfaces, the embedding effect will be more pronounced. Therefore, the use of gaskets will exacerbate this effect and further reduce the clamping force of the bolts.
In summary, we can find that although gaskets play an important role in traditional fastening operations, their existing problems cannot be ignored. In contrast, flange bolts have higher stability, better reliability, and lower maintenance costs. Therefore, more and more engineers are choosing to use flange bolts instead of traditional gasket fasteners. Of course, during the replacement process, we also need to pay attention to adjusting the original installation torque to ensure the optimal tightening effect.
