Difference between single mechanical seals and double mechanical seals

Question

Accepted Answer

Single mechanical seals have one seal face while double mechanical seals have two seal faces for better sealing performance.

Single mechanical seals have one set of faces to prevent leakage, while double mechanical seals have two sets of faces for added protection.
Double mechanical seals are more effective in preventing leakage compared to single mechanical seals.
Single mechanical seals are simpler in design and easier to install, while double mechanical seals are more complex but offer better performance in demanding applications.