... the insulating oil, transformer oil, mutual oil, switch oil, dielectric oil and so on. Application: It is mainly used for ... the insulating oil, transformer oil, mutual oil, switch oil, dielectric oil and so on. The series ZYD-I Double-stage ... purifier machines as: 1. Insulating oil purifier/ Transformer oil purifier/ Dielectric oil treatment1.1. Series ZY: Zhongneng vacuum Insulation oil purifier1 ...