All pendants in a dry pipe system must be installed on what?

In a dry pipe sprinkler system, pendants must be installed on goosenecks to ensure proper drainage and maintain the system's effectiveness. Goosenecks are curved fittings that help facilitate the proper flow of water when the system is activated. They also play a crucial role in minimizing water accumulation and potential freezing, which is particularly important in dry pipe systems where water is not present in the pipes until the system is activated.

Using goosenecks allows the installer to position the sprinkler heads in a way that optimizes coverage while ensuring that water can effectively reach the intended areas during operation. Their design mitigates pressure loss and maintains adequate flow from the system when it is activated, thereby providing reliable fire protection.

Other options, such as installing pendants on straight pipes, cables, or brackets, would not provide the necessary functionality required in a dry pipe system and could lead to improper system performance.