Want To Know About Shrink Fitting?

There could be many applications around us where we come across the need of fixing the two components together. Although there are different methods available to join them, but there in no guarantee that the joint will last long. Every day new techniques hit the market and different applications use these techniques in their own way. One such technique in Shrink Fitting. This technique is ideal for conditions when an interference fit in required. This method has replaced the traditional method of fitting a component into another by force lift method or to expand to outer component with heat. As these were traditional methods, there are some disadvantages with them. Force lift method can lead to mechanical damage between the two faces whereas the latter one can cause local damage or stress due to improper or poor heating procedures.

Shrink fitting is found to be a good alternative to applications where fitting is carried out by heating the outer components or force fitting. With Liquid Nitrogen shrink fitting the necessary clearance is obtained by shrinking the inner component (instead of expanding the outer one). This is achieved by immersing the inner component in a bath of Liquid Nitrogen at a temperature of -196C. After assembly the inner component warms up, expanding to form a tight distortion free interference fit.

There are numerous advantages of Shrink Fitting. First it results in great cost savings. Within few seconds, a 4” diameter mild steel shaft can be shrunk by 7.6 in just 20minutes. It means no loss of time during oil bath or furnaces as the component is simply immersed in a bath of liquid nitrogen. The shrunken component is easier to work with than heat treated material therefore, reduces handling time.

Next advantage is its efficiency is ensuring low capital costs. As oil baths and heating furnaces will be removed, you can save huge capital costs. Moreover, you can save on valuable workshop space. The equipment required for Liquid Nitrogen shrink fitting is not only simple but inexpensive as well. One off jobs can be carried out with complete success using a metal bucket, empty oil drum or open tank as the LN bath. Small components can be handled using wires or cords. Larger components may require ordinary slings.

Among various methods of shrink fitting, liquid nitrogen fitting is found to be the safest method as it is inert and therefore reasonably safe to use in a workshop if proper ventilation is provided.

Want to know more about Shrink fitting? With over 20 years experience, Allied Pipefreezing can provide a cost effective solution to fit large or small components by interference.

Visit our website for more information on Shrink Fitting, Hot Tap Connection and Hot Tapping and Line Stopping.