Manholes with a diameter of at least how many inches must be installed in the top of tanks over 5,000 gallons?

Manholes with a diameter of at least 16 inches must be installed on the tops of tanks that hold more than 5,000 gallons. This requirement is in place to ensure that there is adequate access for inspections, maintenance, and any necessary interventions within the tank. A manhole of this size allows technicians and workers to safely and effectively enter the tank, which is particularly important for larger tanks that may require more extensive maintenance or inspection procedures.

The specific dimension of 16 inches is likely established to strike a balance between adequate access and structural integrity, ensuring that the tank remains secure while still providing enough room for personnel or equipment to enter when necessary. In the context of safety regulations and industry standards, such specifications help to promote safe practices and prevent incidents that could arise from inadequate access or maintenance capabilities.