ISO/TS 20656-1:2017描述了埋地玻璃钢管道的分项系数是如何制定的，主要目的是为满足ISO 10639、ISO 10467和ISO 25780以及EN 1796和EN 14364要求的玻璃钢管道定义必要的安全措施。同样的方法也可用于其他管道产品标准，尽管其他参数也适用。

ISO/TS 20656-1:2017 describes how partial factors for buried GRP pipes are developed, and are primarily intended to define the necessary safety measures for GRP pipes that meet the requirements of ISO 10639, ISO 10467 and ISO 25780, and EN 1796 and EN 14364. The same methodology can be utilised for other pipe product standards, although other parameters would apply.