What are Key Kegs or Ball-in-bag kegs designed for?

Key Kegs, also known as Ball-in-Bag kegs, are designed for one-way use, making them disposable after the contents have been served. This design features a flexible bag inside a rigid frame, allowing for the beer to be stored under pressure without exposing it to oxygen, which helps maintain its freshness. The system makes it easy to transport and store beer while reducing the need for traditional cleaning and maintenance associated with reusable kegs. The emphasis on convenience and reducing the risk of contamination makes them an attractive option for venues and breweries that prefer a lightweight, less labor-intensive keg solution.

The other options do not accurately describe the primary function of Key Kegs. They are not reusable or designed for heavy-duty, high-pressure storage, nor do they serve as standard kegs for all beer types.