Category Archives: Industrial Refrigeration Service

Industrial Refrigeration Sludge Service

Industrial Refrigeration Sludge Service

This industrial refrigeration service visit is to remove sludge from the system. There had been a long period of neglect prior to Maximus Chillers attending site, so regular oil changes had not been carried out. Two oil changes have now been carried out and still a small amount of sludge still remains in the system

Industrial Refrigeration Sludge Service

Due to previous industrial refrigeration sludge service and other servicing- the plant was down to about half of its 60kg charge of refrigerant. It was starting to show signs of refrigerant shortage as the machine was preventing loading up. An ammonia suitable pump out unit was used to decant the remaining refrigerant into a cylinder for disposal

Pressure and Temperature

Once this had been carried out, any residual refrigerant in the oil and liquid on the low side of the plant was carefully handled until the plant was at the same pressure and temperature of the surrounding environment. See picture of some remaining liquid boiling off in an oil return vessel on the bottom of the flooded evaporator

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Industrial Refrigeration Sludge Oil Service

Once the pressure and temperatures equalized, our engineer drained the oil in the system from four different vessels. The oil was then removed from site for recycling. Usually, pressure helps with the process, but as the system was empty, gravity was sufficient for most parts of the plant. Nitrogen being introduced to the oil supply pipe to push it back to the oil separator

Flushing Agent

A flushing agent specially formulated for use in ammonia systems was used to aid the removal of sludge and oil from the pipework around the chiller


After a pressure test, the evacuation process was started. This was to boil off any remaining flushing agent, to remove non condensables and remove any moisture. A near perfect vacuum was achieved

Run up

New refrigeration grade anhydrous ammonia was charged into the system, a little at first to check for any leaks. Then, the plant was checked for effective running conditions. All readings were okay with the compressor loading up to 100% before backing off to match the load

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Industrial Refrigeration Service of the Refrigerant

Industrial Refrigeration Service

We recently carried out an industrial refrigeration service to a plant due to a refrigerant leak. The customer had reported that the ammonia leak alarm had gone off and the plant had shut down. When he went to investigate, a strong smell of ammonia was coming from the compound

Industrial refrigeration service

The Leak

We arrived on site promptly, well within our usual call out time. On assessing the situation, our engineers decided to ‘don’ breathing apparatus BA and full length ammonia grade personal protection equipment PPE. The leak was easy to find as anhydrous ammonia was still coming from a 1/4” pipe fitting on an oil return eductor. It had worked loose due to the vibration of the plant. He ‘nipped’ it back up with his adjustable spanner and the leak stopped. After the dispersal period for the leaked ammonia, a trace leak test was carried out to the fitting and the decision was made to ‘doff’ the BA and PPE

Testing the Plant

There was found to be no subcooling in the low pressure receiver, high superheat and the compressor was being held back from loading up. The various sight glasses were showing poor running conditions too. Refrigerant shortage

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Fast Same Day Delivery

The end user was worried that should the other plant need service, he would loose his production. We arranged our fast, same day delivery service of 4x 56 kg ammonia cylinders that arrived in a couple of hours

Industrial Refrigeration Service of Ammonia

Servicing the industrial refrigeration ammonia charge was straight forward. The system has a service port on the header tank. While the system is running, the header tank pressure is considerably lower than the cylinder. Our cylinders come with a dip tube, so liquid is easily sucked into the plant. When the low pressure receiver subcooling came down to nominal readings along with the sight glass readings, we were happy that the plant was back in service

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