spare piston的意思|示意

The pump comes complete and ready to use with a 12.5 foot grout hose and a set of spare piston cups.

该泵构造完整，可以使用12.5英尺水泥浆软管和一套备用活塞。

They are suitable for the piston bars of sludge pumps, nozzles for sludge and spare parts for machines in mining and geological prospecting.

适应于地原矿勘探用泥浆泵活塞杆、泥浆喷咀及机械配件。