For the 366x474 pressure access door, people can go in to check the internal devices and welding pipelines of the drum. The access door, also known as the inspection door, is located on the furnace wall on both sides of the chimney and the rear furnace wall. Its function is that people can enter the furnace for installation, masonry, maintenance, troubleshooting, cleaning the furnace, etc. Elliptical manhole is mainly used for life, and there are also a few applications in industrial production.