Final answer:
To distinguish AN fluid line fittings from A/C fittings, consider their function, design, size, thread pitch, and use of O-rings or gaskets.
Step-by-step explanation:
To distinguish an A/N fluid line fitting from an A/C fitting, you need to understand their function and design. AN fittings are commonly used in applications such as high-performance fuel systems and oil cooling systems, while A/C fittings are specifically designed for air conditioning systems.
The main difference between AN fluid line fittings and A/C fittings lies in their size and thread pitch. AN fittings have a specific size designation that corresponds to their tubing diameter, while A/C fittings typically have standard sizes.
Another difference is the use of O-rings or gaskets. AN fittings use a tapered thread and do not require O-rings or gaskets, while A/C fittings often incorporate O-rings or gaskets for a secure and leak-proof connection.