In order to improve the plasticity of alumina ceramic pipe and meet the size and corrosion resistance in use, hot pressing process is indispensable in production.

1. The purpose of preloading is to prevent the core layer, seam and other defects caused by the displacement of alumina ceramic pipe when it is installed into the hot press. The billet shall be pre pressed at room temperature after assembly and before hot pressing to make it stick as a whole.

2. The hot pressing temperature is about 140oC, the unit pressure is 2.5-3.0mpa, and the hot pressing time is calculated according to the finished thickness of alumina ceramic pipe.

3. The three-stage decompression treatment is a hot pressing post-treatment process. The first stage is from working pressure to "balance pressure", the second stage is from "balance pressure" to zero, and the third stage is from zero to ceramic riser to complete opening to prevent "bubbling".

After the hot pressing treatment of alumina ceramic pipe in the above three aspects, it will meet the application requirements to a great extent. Ceramic risers need clamping connection in many occasions. If this work is not done enough, it will cause a lot of trouble in the later stage. Therefore, it is very necessary to have a specific understanding of this knowledge.