Refrigerator pipework and oil traps
Refrigerator Repair – Pipework assembly
Soft copper tubing up to 22 mm (7/8 in) diameter may be joined with flare fittings or by brazing. Hard drawn copper tubing is brazed. Iron and steel pipework is welded; cost restricts the use of welding to large industrial and ammonia systems, and it is not described here.
Flare fittings
Flare connections will be perfectly satisfactory [...]
Refrigerator Repair – Parallel pipework
When compressors are installed in parallel and share common suction and discharge lines, they are usually open-type units. Hermetic and semi-hermetic units are not used in case of a motor failure. The high temperatures resulting from the motor failure of one motor compressor can cause a chemical breakdown of the refrigerant and oil, resulting in [...]
11Nov2009 | admin | 0 comments | ContinuedRefrigerator Repair – Discharge line mufflers
In the event of noise or vibration from gas pulsations, discharge mufflers are recommended and must be installed for the free draining of oil.
recommended and must be installed for the free draining of oil. As previously stated, when compressors are idle the oil adhering to the inner surfaces of the discharge line risers will drain [...]
Refrigerator Repair – Oil separators
A certain amount of oil leaves a compressor with the discharged refrigerant vapour. Large quantities may be prevented from circulating in the system by using an oil separator. Most air conditioning systems employ one of three basic types; the most common is the float type.
Oil returns to the compressor after it has been collected in [...]
Refrigerator Repair – Oil traps
Suction line oil traps
High suction line risers will inevitably lead to compressor lubrication problems if provision for oil return is not made. When the compressor is located above the evaporator, an oil trap must be installed.
During low suction pressure operation at the end of a cooling cycle, the oil will tend to separate from the [...]
Refrigerator Repair – Pipework routes
When condensing units or remote condensers are located above the level of a coldroom, it is possible that the pipework will pass through a wooden floor. The pipework will be subject to variations in temperature. Condensation can form on a suction line, and if this is insulated the insulation can become saturated.
This will encourage wet [...]
Refrigerator Repair – Pipework supports
Currently three types of supports are used: the tubing saddle for smaller diameter tubing; a more elaborate assembly such as Hydra-zorb for larger diameter tubing; and the Munsen ring for iron and steel pipework, which obviously requires a stronger type of support structure (Figure 69).
Pipework must be well supported. For soft drawn copper tubing, the [...]
Refrigerator Repair – Pipework fittings
Although it is general practice to install pipework where possible with brazed joints, flare fittings are still used. These should be kept to a minimum because too many in a circuit will create a pressure drop.
Flare unions and service and shut-off valve connections do not determine the diameter of the system pipework. It may be [...]