Are the air heaters and cyclone separators used in the PVC industry considered pressure vessels?

This post was last edited by wang*neng on 2010-11-8 at 14:02. It is not a pressure vessel; a container is considered a pressure vessel only if it meets all of the following three conditions: (1) The operating pressure is greater than or equal to 0.1 Mpa (excluding hydrostatic pressure); (2) The inner diameter (for non-circular cross-sections, this refers to the largest dimension) is greater than or equal to 0.15 m. Furthermore, the volume (V) must be greater than or equal to 0.025 cubic meters, and the product of the operating pressure and volume must be greater than or equal to 2.5 MPa·L (where volume refers to the geometric volume of the pressure vessel); (3) The medium contained must be a gas, a liquefied gas, or a liquid whose highest operating temperature is greater than or equal to its standard boiling point. The operating pressures of cyclone separators and air heaters are generally only in the range of a few thousand pascals to several tens of thousands of pascals, so they do not meet the first condition and therefore are not considered pressure vessels.

Air heaters and cyclone separators used in the PVC industry are not pressure vessels.

However, the working pressure on the steam side of the air heater is relatively high; does this make it a pressure vessel?

Reply to 4# yhpsxj: The air heater – the steam side, that is, the coiled tubes, are pressure pipes, not pressure vessels.