Class-based Class I Class I I Class I I I
Design Pressure/MPa Design Temperature/Temperature/MPa Design Temperature/Temperature/MPa Design Pressure/Temperature/MPa Design Temperature/Temperature
> less than
Steam and hot oil 1.6 300 O. 7~1.6 170~300 0.7 170
Fuel 1.6 150 O. 7 to 1.6 60 to 150 O. 7 60
Other media 4.O 300 1.6-4. O 200~300 1.6 200



Note: 1. When one of the design pressures and temperatures of a pipeline system meets the class I specifications in the table, it is defined as a class I pipeline system; when the design pressures and temperatures of the pipeline system meet the class II requirements in the table. It is designated Class II Pipeline System. Other media are air, water, lubricants and hydraulic oils. 3.Grade III seamless steel pipes can be manufactured in accordance with the national standards approved by Sichuan Construction Department. (2) Seamless steel tubes for boilers and superheaters, with wall temperature not exceeding 450 degree C. (2) Size (1) Steel pipe size should be better than the first group of common steel pipe size in Table 1 of GB/T7395-1998. (2) The outer diameter of steel pipes should be selected from the first series of GB/T7395-1998: the outer diameter of standard pipes. (3) Steel pipes of different sizes specified in Table 1 GB/T7395-1998 can be manufactured according to buyer's requirements.