Objective: in a station with several machines, choose the oil by each machine's conditions and the base oil in it, and change the oil without carrying old deposits into the new oil. The 132 kW machine runs hot (display reading about 96 °C at the survey) and was on another manufacturer's PAG-based oil; it was switched to CPI-1522-46, a PAG/ester oil of the same family. The 200 kW machine runs cooler and was given the PAO oil CPI-4601-46. Both were drained completely, the separator tanks cleaned and the separator elements and filters replaced before filling; Hop Tien recommends an analysis sample after 500 hours.
The compressed-air station of a beverage packaging plant in Dong Nai uses machines from several manufacturers. Two screw compressors of 132 kW and 200 kW from two European/American manufacturers were switched to CPI oil in two steps (Nov 2018 and Aug 2019). The question was not "which oil for the whole station" but which oil for each machine: the 132 kW machine runs loaded with a discharge temperature of about 96 °C on the display and was on another manufacturer's PAG (polyglycol) oil; the 200 kW machine runs cooler, had 9,652 machine hours, its previous fill had run 8,000 hours and deposits had settled at the bottom of the separator tank. Changing to an oil other than the machine manufacturer's is done only once the plant has confirmed that the machine is no longer bound to a specific oil under its warranty terms; Hop Tien checks this first on every machine.
132 kW machine: the old PAG oil and CPI-1522-46 (PAG/ester) are of the same family, so a double fill was not needed; the old oil was drained completely from the compressor unit, separator tank, cooler and low points, the separator element and oil filter replaced and the machine filled once; seal and paint materials were checked against the TDS wording. 200 kW machine: the base oil in the machine was checked against the oil label and the machine manual before the PAO oil CPI-4601-46 was chosen; the rule is that with a different base (PAG or ester) a flush or a double fill per TDS is required, and within the mineral/PAO group the old oil is still drained completely and the filter and separator element replaced. Both machines: an analysis sample after 500 hours to confirm that residual old oil has no effect and to set the change interval.
The 132 kW machine was given CPI-1522-46, a PAG/ester synthetic oil for high-temperature, high-humidity environments; the 200 kW machine was given CPI-4601-46, a PAO synthetic oil. On both machines, Hop Tien technicians drained the old oil completely, cleaned the oil separator tank (on the 200 kW machine the tank was removed for cleaning, because deposits from the 8,000-hour fill had settled at the bottom, where the new oil would mix in as soon as the machine ran), replaced the fouled separator element, the oil filter and the air filter, and only then filled the new oil; the machine hours and the oil filled were recorded in each machine's file.
At handover the 132 kW machine ran loaded at 7.2 bar with a display reading of about 96 °C and no alarms; the 200 kW machine ran at 7.0 bar with a much lower discharge temperature, stable. The pressure of 7–7.2 bar is the station's preset working pressure, read on the display at the survey and at handover, not a result of the oil change. Total machine hours (9,652 hours on the 200 kW machine) differ from oil hours (running hours since the fill): the machine file records both to schedule sampling and the replacement of filters and separator elements.
The lesson Hop Tien applies to stations with several machines: one file per machine (machine hours, oil hours, temperature, base oil in use) to choose the oil and schedule filter and separator element changes; never change the oil without cleaning the separator tank and replacing the separator element, because the old element holds old oil and deposits and releases them gradually into the new oil. The analysis sample after 500 hours is the step Hop Tien recommends to confirm the change interval for each machine.
Oil change reports, November 2018 (132 kW machine) and August 2019 (200 kW machine). Plant name and machine makes are withheld in line with Hop Tien's practice.
Objective: verify the hydrocracked mineral air compressor oil CPI-9370-46 under air-compressor conditions in Vietnam (hot discharge, dusty and humid compressor rooms) and use oil analysis to set the change interval for each machine. Six machines at three plants were monitored; this article presents three representative machines. Result: the normal samples held a viscosity of 44–50 mm²/s, within ISO VG 46, and a TAN below 0.5 mg KOH/g up to almost 5,000 hours; the 75 kW machine went on to 7,612 hours on one fill when monitoring ended (last analyzed sample at 4,872 hours); one case of water entering the oil was detected early through routine sampling and dealt with.
Binh Duong (now Ho Chi Minh City), North Central Vietnam, Dong Nai · Aug 2022 – Jul 2023
Objective: fill the ammonia refrigeration compressor oil CPI-1009-68 into four NH₃ screw compressors with 11,400–49,100 running hours without letting old oil and sludge contaminate the new oil. Method: drain the compressor unit and the separator through the machine's oil drain valve, clean the filter, drain every low point until the oil runs clear, and only then pump in the new oil; done during a maintenance stop, without dismantling the machines.
Dong Thap · Oct 2016
Objective: clean the varnish out of a 75 kW screw air compressor with many years of service and switch it to an NSF H1 registered air compressor oil without a long shutdown. Method: run the cleaning oil CPI COMP CLEAN II (not an H1 oil) in production for up to 500 hours per TDS so the varnish dissolves gradually; drain completely, clean the system and replace the filters as recommended; only then fill the H1 oil CPI-4265-46F and monitor by periodic oil analysis according to the plant's maintenance schedule.
Binh Duong (now Ho Chi Minh City) · Mar 2019
Objective: clean the carbon deposits from the chain and guide rails of an 8-chamber stenter before switching to LUBCON TURMOFLUID 40 B chain oil, with a procedure that can be repeated on the other machines: mechanical cleaning, spraying the cleaning oil LUBCON TURMOWOODOIL MKP Cleaner at the chain's working temperature in several rounds, blowing with compressed air, then changing the oil. Results assessed visually (before/after photos) and by the maintenance team's observations.
Dong Nai · 2017
Objective: get data from real machines before changing grease: how long LUBCON grease stays on the draw-frame rollers compared with the grease in use, and which grease suits the spindle bearings of the ring frames (spindle speed about 19,500 rpm) and the open gears. Result: on the draw-frame rollers the LUBCON grease was still in place after at least 18 days (when the trial was stopped), compared with about 9 days for the grease in use; the open gears and the ring-frame spindle bearings were stable after two weeks by observation.
Mekong Delta · Jun 2017