本文件规定了膨胀机/油轨控油环的基本尺寸特征，但未提供完整的产品说明（因为膨胀机？油轨设计因活塞环制造商而异，制造商和客户之间的互动将决定具体的设计细节）。 本文件适用于标称直径为40？mm至140？mm的膨胀机/轨道控油环，用于道路车辆和其他应用的往复式内燃机。它也适用于在类似条件下工作的压缩机活塞环。

This document specifies the essential dimensional features of expander/rail oil-control rings, without providing a complete product description (because expander？rail designs vary from piston-ring manufacturer to piston-ring manufacturer, the interaction between the manufacturer and the client will determine specific design details). This document applies to expander/rail oil-control rings of nominal diameters ranging from 40？mm to 140？mm for reciprocating internal combustion engines for road vehicles and other applications. It also applies to piston rings for compressors working under analogous conditions.