What type of plugs are used for temporarily plugging blocked tubes in heat exchangers?

Tapered phenolic plugs are the correct choice for temporarily plugging blocked tubes in heat exchangers. These plugs are specifically designed to create a tight seal within the tubes, preventing leaks and maintaining system integrity while repairs or maintenance are carried out. The phenolic material is durable and can withstand high temperatures and pressures commonly found in heat exchangers, making them suitable for this application.

Tapered design allows for easy insertion and removal, providing a secure fit that minimizes the risk of the plug accidentally dislodging. Additionally, their usage helps to prevent cross-contamination during maintenance by effectively isolating the blocked section from the rest of the system.

Other types of plugs, such as blind nipples and standard taper plugs, may not provide the same level of sealing efficiency or material compatibility with the conditions in heat exchangers. Rubber plugs, while flexible and easy to use, may not withstand high temperatures or harsh chemical environments as well as tapered phenolic plugs, making them less suitable for long-term use in such applications.