BS ISO 18421:2016规定了救生圈外壳的结构和尺寸。外壳用于包裹一个救生圈，以防止其因恶劣天气而变质 反对破坏公物。交叉引用:ISO 2768-1ISO 18422IEC 60945购买本文件时可获得的所有现行修订版均包含在购买本文件中。

BS ISO 18421:2016 specifies the construction and dimensions of housing for lifebuoys.The housing serves to encase a lifebuoy to protect it against deterioration from the elements and against vandalism.Cross References:ISO 2768-1ISO 18422IEC 60945All current amendments available at time of purchase are included with the purchase of this document.