UL 311 BULLETIN-2007《UL安全标准.组装房屋和游乐车辆用液压顶柱》
Covers roof jacks for extending the flue pipe from gas- and oil-fired appliances through the roof structure of mobile homes and recreational vehicles. These roof jacks are intended to be installed in accordance with NFPA 501C, Recreational Vehicles, and the Federal Mobile Homes Construction and Safety Standards.