8.2　Flue

Ⅰ　Dominant Items

8.2.1　The finned tube of flue must be unobstructed.

Quantity to be checked:100%.

Inspection method:Check the qualified certificate for ball-passing test，and observe whether the header is free of sundries and the tube orifice is unobstructed.

8.2.2　In case of welding for flue assembly，the WPQ shall be carried out with report，based on which the welding procedure and the operation instruction for welding shall be determined or prepared.

Quantity to be checked:100%.

Inspection method:Check WPQ report and the operation instruction for welding.

8.2.3　The quantity of butt welds in case of flue assembly shall meet the requirement of the design technical document or that of Safety Technical Supervision Code for Steam Boiler in case of no requirement in the above document.

Quantity to be checked:Comply with the requirement of Safety Technical Supervision Code for Steam Boiler.

Inspection method:Observe or check with a magnifier，and check the ultrasonic or radiographic inspection records.

8.2.4　After completed installed，the flue shall be involved in the hydrostatic test of the system，which shall comply with the requirement of the design technical document.If no requirement in the document，the following requirements shall be complied with:booster its pressure to the test pressure which shall be 1.25 times of the working pressure and hold for 20min，and then lower it to the working pressure and check whether there is water leakage or abnormality during the test；the pressure shall not change.

Quantity to be checked:100%.

Inspection method:Observe，and check the pressure test record.

8.2.5　The installation of spring support for flue shall ensure that the precompression length of the spring shall meet the requirement of the design technical document，the bearing face of the spring shall be vertical to its forced direction and that various sets of springs shall be evenly stressed.

Quantity to be checked:Randomly check at least three groups.

Inspection method:Observe and check the prepressed record of springs.

Ⅱ　General Items

8.2.6　The allowable deviation for flue installation shall comply with the requirements in Table 8.2.6.

Quantity to be checked:100%.

Inspection method:See Table 8.2.6.