Shell as used herein shall mean all pressure holding parts of the vessel in contact with the service fluid, including heads, nozzles, manholes and manhole covers.
这里的壁板指与系统介质接触的所有压力部件，包括封头、设备口、人孔及人孔盖板。
2
The paper introduced briefly produce quality control in pressure vessel′s shell and manhole nozzle welding, how avoided crack and found defect by ultrasonic testing after welding.