What are hollow bolts primarily used for?

Hollow bolts are primarily used for applications that require the flow of water or other fluids. In this context, their main function is related to flush outs and hydrants. The design of hollow bolts allows them to pass through a structure, enabling the attachment or connection point to allow for fluid movement, which is particularly important in the operation and maintenance of hydrants or systems needing drainage or flushing capabilities. This ability to facilitate fluid flow is crucial in waterworks applications, where proper drainage and access are necessary for system maintenance and functionality.

Using hollow bolts in flush outs and hydrants ensures that procedures can be performed efficiently without necessitating the complete disassembly of the connections involved, thereby saving time and labor during operations. Other options, while relevant to different types of fasteners, do not capture the specific fluid-conducting purpose that hollow bolts serve in waterworks applications.