8.2　Installation of Risers and Crossover Mains

8.2.1　Before the installation of the risers，the center lines of bases of the risers shall be checked，and the allowable deviation of the bases of any two risers shall be 3.0mm.

8.2.2　The risers and crossover mains should be in position in the cold state and adjusted in the thermal state.The risers and crossover mains shall be connected temporarily before oven temperature reaches 650℃oven temperature reaches 650℃the risers shall be fixed after the gaps around the birdmouths of the risers and the water seal valve are adjusted to be uniform and jamming does not exist.

8.2.3　After the water seal covers of risers are installed，and the check of water seal height and leakage test are performed according to the requirements of design documents，and the allowable deviation of water seal height shall be±5mm.

8.2.4　After the water seal covers of risers are installed，counter weight shall be adjusted，so that it cannot be closed automatically after being opened.

8.2.5　The rotation of high and low-pressure liquid ammonia conversion mechanism shall be flexible，the opening and closing state shall be correct，and liquid ammonia shall have good spraying and shall be prevented from being sprayed in the coking chamber.

8.2.6　After risers，crossover mains and water seal valves，etc.are installed and adjusted，damaged painted positions shall be coated again.

8.2.7　The installation of risers shall be in compliance with the following requirements:

1　The centers of riser bodies are adjusted，and the allowable deviation of the centers of any two risers shall be 3.0mm；

2　The elevations of top covers of risers are adjusted，and allowable deviation shall be±5.0mm；

3　The perpendicularity of riser bodies are adjusted，and allowable deviation shall be 1/500 of heights of riser bodies.