Refrigerant charging onboard ship

• Normally refrigerant in the liquid state is changed at the high-pressure side.
• Weigh the bottle with a spring scale.
• Connect the charging pipe between liquid valve of bottle and charging valve (ensure air is purged out the collecting cylinder).
• Fully open bottle liquid valve, charging valve is still closed.
• Close main liquid stop valve is outlet from condenser (or receiver) & run the compressor, so that system (compressor stop on  lp cut out) is starved of refrigerant - carry out short cycling.
• Slowly open charging valve (avoid frosting on suction pipe). changing to be done in stages. After filling compressor is shut down & cooling water kept for some hour. (3/4 of sight glass).
• Then air can be purged out from air vent valve of condensor.

Charging connection:

Liquid (blue) - between the receiver and Silva gel filter or through filter gas(red) - before the suction valve.

• Silica gel filter has been replaced by the desiccant, which is a filter and depends on the type of refrigerant used

• To purge charging line after charging refrigerant, valve 1&3 to be in close position and valve 2 to be open & run compressor.

• We can also use a vacuum pump instead of an empty bottle to purge the charging line.

• HP charging connection is provided between receiver and dryer (filter) or through a filter. LP charging connection is provided at the suction of compression. (generally avoided).