| 摘要 |
PURPOSE:To exchange a phosphate hydraulic liquid to a water-glycol hydraulic liquid without lowering the rust-preventive property and lubricity nor generating scum, by using dipropylene glycol, etc., as an intermediate solvent and extracting a phosphate hydraulic liquid using the intermediate solvent with minimum number of flushing operations. CONSTITUTION:In the exchange of only the hydraulic liquid of a hydraulic system containing a phosphate hydraulic liquid, the phosphate hydraulic liquid is extracted from the hydraulic system with minimum number of flushing operations and exchanged to a water-glycol hydraulic liquid by using an intermediate solvent comprising dipropylene glycol or low-molecular weight polyalkylene glycol preferably added with a small amount of a solubilizing agent. |
