8.4　Piping for Steam and Water Systems

Ⅰ　Dominant Items

8.4.1　In case of piping welding，WPQ shall be carried out with corresponding 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.

8.4.2　The quality of welds in case of piping welding 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 the design technical document or that of Safety Technical Supervision Code for Steam Boiler.

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

8.4.3　The positions and forms of piping supports shall conform to the requirements of the design technical document.

Quantity to be checked:100%.

Inspection method:Observe，or check with a ruler.

8.4.4　The hydrostatic test ofpiping shall meet the requirement of Article 8.2.4 of the Code.

8.4.5　After completely installed，the piping shall be flushed to ensure that the color and transparency of water at the sewage outlet is consistent with that of water at the inlet via visual inspection.

Quantity to be checked:100%.

Inspection method:Check the flushing and purging record，and observe.

Ⅱ　General Items

8.4.6　The allowable deviation for piping installation shall comply with the requirements in Table 8.4.6.

Quantity to be checked:Randomly check 10%.

Inspection method:See Table 8.4.6.

Table 8.4.6　Allowable deviation for piping installation

Table 8.4.6（Continued）

Note:L refers to the effective length of pipe and DN refers to the nominal diameter of pipe.