What type of connectors may be used on oil piping in residential installations?

Flexible connectors are commonly used on oil piping in residential installations due to their ability to accommodate movement and vibration in the piping system without causing leaks or damage. They are designed to absorb thermal expansion and contraction, which is particularly important in systems where temperature fluctuations may occur. The flexibility also allows for easier installation in tight spaces and reduces stress on the joints.

In contrast, while rigid connectors might be used in some situations, they do not offer the same level of flexibility, which can lead to potential failure under dynamic conditions. Soldered connectors, typically seen in plumbing systems with copper tubing, are not suitable for oil piping due to concerns about durability and the risk of joints failing under the weight of the oil or due to temperature changes. Metallic connectors, although they provide a strong connection, may not possess the flexibility needed for proper movement management in residential oil piping, making them less ideal for these applications.