What are the two classifications of manways on towers?

Manways on towers are classified primarily into internal and external types based on their design and function. Internal manways are designed to provide access to the interior of a tank or vessel, enabling maintenance, inspections, or cleaning. These manways are typically more secure, featuring forms such as hatches or doors that protect the contents and provide worker safety.

External manways, on the other hand, are located on the outside and allow access to various components without needing to enter the tank. This type of access is crucial for functions such as monitoring, servicing, or managing the equipment attached to the tower.

Understanding the distinction between internal and external manways is vital for safety and operational efficiency in handling machinery and equipment within industrial settings. The other classifications do not accurately represent the specific access types used for manways, as they pertain to different characteristics unrelated to access types in tower structures.