Introduction

Blind flanges and blank flanges are commonly used in the metalworking and pipeline industry. Although they look to be the same, they actually have some distinct differences.

In this post, let’s discuss what’s the difference between a blind flange and a blank flange so that you can purchase more suitable products for your project.

What is a Blind Flange?

A flange without holes in the center is called blind flange, which has a very firm surface that is commonly fixed on pipes and other equipments with bolts.

It is mainly used for sealing the pipe opening to completely isolate the medium.  

Compared with pipe plugs and pipe caps, blind flanges are a more economical and effective way to seal pipes, because it is a detachable device that is easy to replace and convenient to maintain.

What is a Blank Flange?

A blank flange looks the same as blind flange, but there is a major difference is that blank flanges have a hole in the center.  

Blank flange is typically used when pipe and equipment requires pressure testing, cleaning, maintenance, etc., but does not require cutting.

However, due to it has a hole, it’s not suitable for long-term use in systems where there will be pressure or flow through it. Otherwise, it may leak over time due to wear and tear of the gasket material.

Difference Between Blind Flanges and Blank Flanges

Different definition

The blind flange is a kind of flange that has no hole in its center, while the blank flange is a type of flange that has a hole in its center.

Different applications

Blind flanges are used when a pipe needs to be sealed and no gas or fluid is required to pass through the pipe.

Blank flanges are used when a pipe needs to be closed off, but there is still gas or fluid passing through the pipe.

Different functions

Blind flange plays the role of isolation and cutting. Due to its good sealing performance, it is usually used as a reliable means of isolation in pipelines or other equipments that require complete isolation of the medium.

Blank flange has a hole (or opening) in its middle that allows for pressure testing or hydraulic flow through the system.

Different characteristics

Blind flange is a detachable sealing device available in all sizes and classes, easy to replace and maintenance. In addition, the blind flange is bolted so that it is easier to access the inside of the container or pipe.

Blank flanges can’t be used for long-term in systems where gasses or fluids pass through them, as they may leak on account of the wear and tear of the gasket material.

Different materials

Blind flanges are commonly made of forged steel or cast iron.

Blank flanges can be made of any material that is compatible with the rest of the piping system.

Conclusion

In conclusion, although blind and blank flange look very similar, a careful study of the two is actually very different. The most obvious difference is that the blind flange has no hole in the middle, while the blank flange has a hole.

Understanding these differences between blind flanges and blank flanges can help you purchase more suitable products for your project.