What is the term used for the openings in most 55-gallon drums?

The term used for the openings in most 55-gallon drums is "bungs." These bungs are designed to provide access to the interior of the drum for filling, emptying, or sampling the contents. They are usually threaded closures that can be sealed tightly to prevent leaks and contamination, often equipped with a gasket or sealing material to enhance their effectiveness.

Bungs can come in different sizes and types, contributing to the overall functionality of the drum based on the materials being stored. This design feature is crucial for safely containing hazardous materials, as it helps maintain the integrity of the containment system.

Other terms such as nozzles, adapters, and valves refer to different types of fittings or mechanisms that may be used with other containers or systems but do not apply specifically to the openings in 55-gallon drums. Each of these components serves unique purposes in various applications, but in the context of 55-gallon drums, "bungs" is the accurate terminology.