7.2　Assembly and Erection of Flue Gas/Air Ducts and Fuel/Bulk Material Pipes

7.2.1　When the assembly of pipes is carried out，the installing craters shall be reserved in the locations for easy construction.

7.2.2　Any pipe assembly component shall have proper stiffness.If necessary，the temporary reinforcement shall be done.

7.2.3　The pipe clearance shall be even.The surface of gas-cut end shall be ground smoothly.

7.2.4　There shall be sealing liner whose thickness shall be enough between the pipe and equipment flanges.The liner shall be installed inside the flange bolts，which shall not be inserted into the pipe and equipment.The both sides of the liner shall be pasted with the sealing coating.

7.2.5　The welds in the components must pass the oil leak test before insulation.

7.2.6　When the pipes and mechanical equipment are connected，the forced connection shall not be allowed.

7.2.7　After the erection of the pipes，the elevation deviation shall not exceed±20mm.The longitudinal and transverse position deviation of the pipes shall not exceed 30mm.

7.2.8　After the erection of pipes，pressure decay test for the complete boiler shall be carried out to inspect the tightness.Any leakage found shall be recorded and treated in time.If any vibration is found，the reasons should be analyzed to eliminate it.

7.2.9　Before the erection of valves and flanges in fuel/bulk material pipes，the specifications，materials and technical parameters shall be checked according to the design requirements.The installation position shall be convenient for operation and maintenance.