Final answer:
Soft-soldered brazed fittings are not typically allowed because they can lead to rapid corrosion, especially with Cu/Fe pipe joints, which compromise the integrity of the plumbing system.
Step-by-step explanation:
Are soft-soldered brazed fittings allowed? The answer is No, they are not typically allowed. This is because when different metals such as copper (Cu) and iron (Fe) are joined together, it can lead to rapid corrosion due to galvanic action. This corrosion can weaken the joint, leading to leaks or failure of the piping system. Therefore, the use of soft-soldered brazed fittings, especially in permanent or long-term plumbing installations, is not advisable. It's important to choose appropriate fittings and solder materials compatible with the pipes used to ensure a reliable and durable installation.