What maximum fill level should not be exceeded when filling a cylinder with refrigerant at ambient temperature of 70°F?

When filling a cylinder with refrigerant, it is crucial to adhere to safety and operational standards to prevent overfilling, which can lead to dangerous pressure build-up. The maximum fill level of 80% is recommended because this allows for the expansion of refrigerant that occurs with temperature changes.

At 70°F, filling a cylinder to 80% of its capacity provides adequate space for the refrigerant to expand without exceeding the pressure limit of the cylinder. If a cylinder were filled to a higher level, such as 90% or 100%, there would be insufficient space for vapor expansion, posing a significant risk of overpressure, which can lead to cylinder rupture or other hazardous situations.

The choice of 80% ensures a safe operational margin, accommodating variations in ambient temperature and refrigerant pressure. Therefore, maintaining this fill level is essential for the safety of the technician and the effective functioning of the refrigeration system.