B30。4适用于电动机或内燃机驱动的门座式起重机和基座式起重机的建造、安装、操作、检查、测试和维护，这些起重机通过吊臂变幅机构或横穿水平吊臂的小车调整工作半径，可安装在固定或移动基座上，以及保留相同基本特征的任何变化。本标准仅适用于使用卷筒和钢丝绳进行起重的门座式起重机，以及用于起重作业的门座式起重机。本标准不包括塔式起重机（参考ASME B30.3）、伸缩臂起重机（参考ASME B30.5）和转向节臂起重机（参考ASME B30.22）的要求。

B30.4 applies to the construction, installation, operation, inspection, testing and maintenance of electric motor or internal-combustion engine powred portal and pedestal cranes, that adjust operating radius by means of a boom luffing mechanism or by means of a trolley traversing a horizontal boom, that may be mounted on a fixed or traveling base, and to any variation thereof that retain the same fundamental characteristics. This standard applies only to portal and pedestal cranes utilizing a drum and wire rope for hoisting and which are used for hoisting work. The requirements for tower cranes (refer to ASME B30.3), telescopic boom cranes (refer to ASME B30.5), and knuckleboom cranes (refer to ASME B30.22) are not included in this standard.