Why should 95/5 solder be avoided on the discharge line of a refrigerant system?

The choice to avoid using 95/5 solder on the discharge line of a refrigerant system stems from its tendency to lose strength and become more susceptible to leaks when exposed to the operating conditions typical of refrigerant systems. Specifically, the high temperatures associated with the discharge line can lead to the solder becoming weak over time. This weakening can compromise the integrity of the joint, increasing the likelihood of leaks, which can be detrimental to system efficiency and may pose safety hazards.

In contrast, while the other options may present important considerations in different contexts, they do not directly speak to the critical issue of joint integrity under the operational stresses faced by the discharge line in a refrigerant system. For instance, the melting point of solder is indeed important, but the primary concern here relates to the structural reliability of the joint when subjected to varying temperatures and pressures, which the 95/5 solder struggles with due to its composition. Similarly, while corrosion and compatibility with refrigerants are valid concerns for different types of solder in other applications, they do not directly relate to the primary reason for avoiding 95/5 on the discharge line specifically.