True or False: Dissimilar metals should not be joined together as they promote corrosion.

The assertion that dissimilar metals should not be joined together because they promote corrosion is grounded in the principles of galvanic corrosion. When two different metals are in electrical contact in the presence of an electrolyte (like water), the less noble metal can corrode faster than it would if it were not in contact with the more noble metal. This is due to the electrochemical potential differences between the metals, leading to accelerated corrosion of the anodic (less noble) metal.

In contexts such as underground storage tank (UST) installations, where environmental conditions can include moisture and potential electrolytes, the risk of galvanic corrosion becomes significant. Therefore, proper insulation or separation techniques are employed to prevent dissimilar metals from contacting each other, ultimately extending the lifespan of the installation and reducing maintenance needs.

Understanding this concept is crucial in the field of UST installations and retrofitting, as it affects material selection and component compatibility. Thus, stating that dissimilar metals should not be joined together due to corrosion risks is indeed true.