... pressure for the insulation equipment3. Retrieve and store SF6 gas and check the remaining vacuum pressure of the insulation ... air compressor, bumper, separator, filter, heat exchanger, safety valve, one-way valve, gas pressure gauge, vacuum gauge, and freezer;L. Vacuum ... 1.5), vacuum gauge, process diagram and operation guide, valve number, and inlet and outlet indicator.P. InstrumentsII. Technical ...