6　Boiler Attached Pipes and Accessories

6.1　General Provisions

6.1.1　This chapter is applicable to the construction and acceptance for the blowdown，sampling，heating，drain and discharge，vent，desuperheating water，start-up system，soot blowing，water level indicator，safety valves，and other equipment and pipes within the scope of boiler proper.

6.1.2　PMI（Positive material identification）shall be carried out one by one to alloy steel pipes，pipe fittings，pipe accessories and valves before using.And the corresponding material shall be marked.

6.1.3　The pipes，supports and hangers arranged at the site shall meet the following requirements:

1　The secondary design should be carried out to the pipe arrangement.The alignment shall be reasonable and short.The drain slope shall be standard.The expansion compensation shall meet the requirements of piping expansion.

2　The supports and hangers shall be arranged reasonably and firmly，and the piping system shall be arranged orderly and expand freely.

3　The flow direction of the medium shall be confirmed upon the installation of valves.

4　The installlation positions of the valves and actuators shall facilitate the operation and maintenance.

6.1.4　For the erection of the electric（pneumatic）devices in the valves，the travel switch positions shall be adjusted accurately.Furthermore，the over torque protection test shall be carried out according to the requirements.

6.1.5　The hardness inspection of alloy steel bolts shall comply with the requirements of Article 5.1.16 in this Part.

6.1.6　The pipes and throttle equipment in which the throttle valves，the flowmeters and other equipment are designed shall be erected after chemical cleaning，flushing and blowing of pipes have been carried out.