What material is specifically mentioned to be resistant to the action of liquefied petroleum gas?

The material specifically mentioned as resistant to the action of liquefied petroleum gas (LPG) is the thread compound. This is particularly important in propane applications because a suitable thread compound helps ensure that connections between various components are leak-free. Thread compounds used in propane systems are specially formulated to resist the chemical properties of LPG, which can be more aggressive than other gas types.

In contrast, while metal pipes may generally withstand LPG, they can be susceptible to corrosion if not properly treated or coated, especially in certain environments. Plastic fittings often have limitations when exposed to hydrocarbons like propane, as they can degrade or become brittle over time. Rubber seals might also be vulnerable to the effects of liquefied petroleum gas, leading to potential failures. Thus, using thread compounds that are expressly designed for LPG applications ensures reliability and safety within gas systems.