What type of packing is constructed from 100% graphite?

The correct answer is the type of packing constructed from 100% graphite, which is indeed corrugated ribbon packing. This type of packing is designed to provide superior sealing ability in high-temperature environments. The graphite material allows it to withstand significant thermal and chemical stresses, making it suitable for various applications, especially in steam and thermal systems within marine environments.

Corrugated ribbon packing is specifically engineered using pure graphite, which enhances its flexibility and conforming ability to irregular surfaces, ensuring a tight seal. This characteristic is essential in preventing leaks in critical piping and mechanical systems.

The other types of packing mentioned in the options do not consist of 100% graphite. Rubber packing typically includes elastomers and is not suited for high-temperature applications. Plastic packing is made from synthetic materials, which may not have the same heat resistance or sealing capabilities as graphite. Composite packing combines various materials, which also means it does not consist solely of graphite. Thus, corrugated ribbon packing stands out as the definitive choice when discussing packing made entirely from graphite.