What is a common characteristic of a "D" type boiler?

A "D" type boiler is characterized by its design, which includes two drums. This configuration typically consists of a steam drum located at the top and a water drum at the bottom, with the arrangement allowing for efficient separation of steam and water. The dual-drum setup in a "D" type boiler promotes better circulation and thermal efficiency due to the water and steam mixtures traveling vertically through the heating surfaces.

This design also enhances the boiler's ability to handle varying loads, making it suitable for industrial applications where demand may fluctuate. The steam produced is of high quality, owing to the effective separation method employed in a two-drum setup. Therefore, the distinguishing feature of a "D" type boiler is its use of two drums, making it ideal for efficient steam generation.