For boilers over 36 inches tall and with more than 100 square feet of surface area, how many gauge cocks are required?

For boilers that exceed 36 inches in height and have more than 100 square feet of heating surface area, the requirement is to install three gauge cocks. This is based on safety regulations established to ensure proper monitoring of water levels and pressure within the boiler system.

The inclusion of multiple gauge cocks allows for more accurate readings and redundancy. If one gauge were to malfunction, the other gauges can provide critical information regarding the boiler's operation. This is particularly important in high-pressure systems where maintaining correct water levels is vital for safe and efficient operation. The requirement for three gauge cocks contributes to overall safety by helping operators ensure that the boiler functions properly and maintains appropriate water levels, reducing the risk of dangerous conditions.

Therefore, having three gauge cocks serves a significant purpose in the operational safety measures mandated for larger and taller boilers.