Pneumatic ball valve is mainly used in places with high temperature and small section size. The pneumatic ball valve is composed of upper and lower guide tubes, sealing filling materials and pipe sleeves. When the pipe length changes due to temperature change, the upper and lower guide cylinders of the pneumatic ball valve will shift along the axial direction of the pipe. Since the upper and lower guide cylinders of the pneumatic ball valve are filled with a certain elastic fire-resistant filler, the seal can still be ensured when the guide cylinder moves. In order to reduce the fluid resistance at the pneumatic ball valve, a guide liner can be set inside the pneumatic ball valve.
The liner is welded with the shell of the heat exchanger at one end facing the flow direction of the fluid, and the other end can be freely retracted. The thickness of the liner of the pneumatic ball valve shall not be less than 2mm, and shall not be greater than the thickness of the pneumatic ball valve. The length shall exceed the wavelength of the pneumatic ball valve. The pneumatic ball valve of the horizontal heat exchanger must be equipped with a liquid discharge interface at the * low point of its installation position, so that the liquid can be discharged completely during shutdown. It is usually plugged with a threaded plug.