Does it have any effect on heat transfer?

Friends who are familiar with alfa laval products should know that the common hanging holes of alfa laval are as follows: oval and swallowtail.

 

So in what scenarios are these two specific applications? 
A knowledgeable friend should say that the circular hanging hole is generally a small plate type, and the dovetail type is a large plate type.

Yes, that's right. Alfa laval M3 to M10 series are all round hanging holes. The corner hole diameter f is not more than 100mm, and the corner hole diameter exceeds 100mm, such as the small 105mm TL10P and the medium 140mm M15. 

The 230mm MX25 is of this dovetail type.

The logic is easy to understand. The guide rod of the circular hanging hole is also round, while the dovetail type screw is a "I"-shaped screw, as shown in the figure:

When installing, the circular hanging hole can be installed directly, while the dovetail type needs to be hung.

In this case, does it feel weird, why do the plates that have been drilled and formed need to be processed twice in the hanging holes? 
And why do other dovetails, some processed and some not processed?

Generally, this kind of situation will only appear in very large version, which is used for reinforcement. Although the design pressure is around 25bar, the larger the general version, the larger the flow rate and the higher the flow rate. The actual pressure is 
Also higher.

Therefore, in order to ensure the stability of product operation, these details must be in place.