5.2　Steam Drum，Steam-water Separator and Header

5.2.1　Before the assembly and erection of equipment，all internal surfaces in the headers must be cleaned.The inspection shall be carried out with the endoscope to the boiler headers that are equipped with the throttle devices.There shall be no plugging in all tube connecting seats.The"drilling plates"，commonly called as glass lens，shall be cleaned completely.

5.2.2　Steam drum，steam-water separator and the header may be lifted after boiler steel structures has been aligned and fixed.When aligning steam drum，steam-water separator and the header，the measurement shall be carried out in accordance with the framework center line and the re-inspected drilled marks in steam drum，steam-water separator and the header，and the erection elevation shall be with reference to the framework 1m elevation location.

5.2.3　The allowable deviation for the erection of the main equipment such as steam drum，the steamwater separator，the header and so on shall be listed as follows:

1　Elevation:±5mm.

2　Levelness:Steam drum:2mm，Header:3mm.

3　Mutual distance:±5mm.

4　Verticality:1/1000 of the length and it shall not exceed 10mm.

5.2.4　For hoisting rings of steam drum，the contacting locations shall be checked before the erection.The contacting angle shall be within 90°.The contacting locations shall be in good contact.The arcs shall be anastomotic，and the requirements of the manufacturing equipment technical documents shall be met.

5.2.5　The hanging devices for steam drum，the steam-water separator，the header shall meet the following requirements:

1　The connections of the lifting lugs，hangers，lifting plates，pin shafts and so on of the hanging devices shall be firm and the welding shall meet the design requirements.

2　The powder lubricant shall be coated between the spherical pad irons.

3　The hanger tightening load shall be uniform distribution.The re-inspection shall be carried out to the hanger forces before hydrostatic test.

5.2.6　After the erection of the internal devices of steam drum and the steam-water separator，the following provisions shall apply:

1　The component installation position shall be correct.

2　The connection dampers for the steam，feed water and other applications shall be tight and without leakage.There shall be no crack and leakage in the welds.

3　All flange joining surface shall be tight.The connecting pieces shall be equipped with the locking devices.

4　Before the closing operation is carried out，the internal sundries inside steam drum and steamwater separator shall be removed.

5　After the erection of the key connecting pieces，spot welding shall be firm.

5.2.7　Striking arc and welding shall not be carried out in steam drums，steam-water separators and headers.Otherwise，the approval must be obtained from the manufacturer，and the strict welding procedure qualification shall be carried out before welding.

5.2.8　Before closing all headers，the internal cleanness shall be inspected to the headers.The closing operation may be carried out after it has been confirmed that there shall be no foreign thing，and the certification for concealed works shall be handled.