Non-metallic vessels are sometimes utilized in which of the following services?

Non-metallic vessels are often utilized in corrosive services due to their resistance to a variety of harmful chemicals that can cause degradation in metallic materials. These vessels can be made from materials such as fiberglass reinforced plastic (FRP), which provides excellent corrosion resistance for a wide range of aggressive substances, including acids, alkalis, and solvents. The inherent properties of non-metallic materials allow them to maintain structural integrity and prevent leaks in environments where traditional metals would corrode.

In contrast, high-pressure gas services typically require materials that can withstand significant mechanical stresses, and although some non-metallic materials might be able to handle this condition in specific applications, they are generally not the first choice for high-pressure scenarios due to strength limitations.

For vacuum systems, while non-metallic materials can be used, it is essential that they have appropriate strength and thermal characteristics to prevent collapse under vacuum conditions.

Also, in bulk liquid storage, while there may be some applications of non-metallic vessels, metals are often preferred due to their durability and structural capabilities needed for large-scale storage. Hence, utilizing non-metallic vessels in corrosive services is a prime application due to their advantageous properties against chemical attack.