MIC Information: Tubercles

Tubercles are the end product of Biofilms. Removing them can cause pitting, pin-hole leaks, and other dangerous problems.


What is a Tubercle?

A tubercle is a mound created on the metal’s surface that creates a micro-environment for the various species of bacteria to thrive together in a colony.

A tubercle formation starts with the creation of a Biofilm upon the metal surface.

What is the Purpose of a Tubercle?

A tubercle protects anaerobic bacteria (without oxygen) from the outside environment.

A tubercle’s outside shell is actually composed of aerobic bacteria (oxygen breathing) and their by-products.

The aerobic bacteria provide nutrients for the anaerobic bacteria.

The anaerobic bacteria processes the surface of the pipe and derive energy from reduction, taking oxygen away or oxidization of the surface of the pipe.

Some anaerobic bacteria provide needed nutrients for aerobic bacteria in return.

Why are Tubercles a Problem?

Buildup of tubercles and other corrosion deposits reduce the diameter of the pipe interior and affect the flow rate of the water and performance of the system. They can eventually completely block the pipe.
Tubercles can break off during the activation of a Fire Protection System, plugging sprinkler heads and endangering both life and property.