5.2　Assembly and Installation of Gas Duct

5.2.1　The gas duct fabrication shall be in accordance with the following requirements:

1　The specification and dimension of gas duct raw material shall comply with the design documentation regulation；

2　The separation distance of duct longitudinal weld shall not be less than 200mm；when carry out duct jointing，cross weld is prohibited；

3　The weld quality shall comply with the regulation of design documentation，the defects of missing weld and nonpenetration are prohibited.The kerosene penetration test to duct weld shall be qualified and carried out with test record.

5.2.2　The fabrication of the gas duct shall be in accordance with the following requirements:

1　Before assembly，the dimension of gas duct shall be confirmed according to those factors like the practical gas duct storage，transportation，hoisting passage dimension，etc；

2　After the assembly of gas duct，the kerosene penetration test shall be qualified and carried out with test record.

5.2.3　The gas duct installation shall be in accordance with the following requirements:

1　The fabrication and installation of tube supports shall meet the relevant requirements of the current national standard Code for Acceptance of Construction Quality of Steel Structure GB 50205 and Code for Welding of Steel Structure GB 50661；

2　After installation，the supports and brackets shall be well contacted with the gas duct with balanced stress；

3　During hoisting，the assembling units shall have sufficient rigidity；

4　The gas duct innerwall insulation and wear-resisting lining should be constructed after the gas duct installation is set up，the applied material and construction technology shall comply with the design documentation regulations.The lining surface shall be smooth；

5　After the gas duct installation is completed，clean the debris of duct interior or exterior，and removed the temporary fastening components.

6　The connection of gas duct of waste heat boiler and cement production line must be carried out after the cement production line is stopped and tube surface temperature is lower than 50℃.

7　The connection engineering of gas duct of waste heat boiler and cement production line shall be in accordance with the following requirements:

1）The construction scheme shall be prepared before the construction，and safety measures and emergency response plans shall be provided；

2）After the connection is completed，the relevant parties shall sign to confirm the project quality.