8.10　Gas Blow-off Valve and Equalizing Valve on Top

8.10.1　Before the installation，the gas blow-off valve and the equalizing valve shall be put on the rack or the platform under the working condition，the joint surface of the valve seat and the valve pedal shall be checked by the feeler gauge，and the seal degree shall meet the requirements of the design document.The requirements of Appendix E of this standard shall be met when there is no requirement in the design document.

8.10.2　The allowable deviation of the longitudinal and transverse centerlines of the hydraulically driven gas blow-off valve and the equalizing valve is 5.0mm，that of the longitudinal and transverse levelness is 0.5/1000，and that of the elevation is±5.0mm.

8.10.3　The allowable deviation of installation of the gas blow-off valve driven by the winch shall meet the requirements of Article 8.10.2 of this standard.

8.10.4　The installation of the driving device of the winch shall meet the following requirements:

1　The longitudinal and transverse centerline of a coiling block shall be checked by steel ruler through drawing the wire and hanging the pendant，with the allowable deviation of 5.0mm.

2　The elevation of the center line of the coiling block shall be checked by level gauge or steel ruler，with the allowable deviation of±10.0mm.

3　The levelness of the coiling block or the base shall be checked by leveling instrument and levelling ruler or the perpendicularity of the end face of the coiling block shall be checked by hanging the pendant，with the allowable deviation of 0.5/1000.