Identify a common violation that may occur in mechanical installations.

Improper venting of appliances is indeed a significant violation that can occur in mechanical installations. This issue can lead to serious safety hazards, including the potential buildup of harmful gases such as carbon monoxide. Proper venting is crucial for ensuring that combustion gases are safely expelled from a building into the atmosphere, preventing these gases from accumulating indoors where they can pose health risks to occupants.

In mechanical systems, appliances like furnaces, water heaters, and stoves must be vented correctly to function efficiently and safely. Failure to do so can result in inadequate exhaust of combustion products, increasing the risk of fire and affecting indoor air quality. Therefore, compliance with applicable codes and proper installation practices regarding the venting of appliances is vital for the safe operation of mechanical systems.

Other violations may be serious, but improper venting distinctly impacts both safety and regulatory compliance, making it a particularly noteworthy concern in mechanical installations.