What is the minimum connection size for sight glasses mounted on most LP steam boilers?

The minimum connection size for sight glasses mounted on most low-pressure steam boilers is 1/2 inch. This standard is established to ensure adequate visibility of the water level within the boiler. A sight glass serves as a critical safety feature, allowing operators to monitor the water level effectively.

Using a connection size of 1/2 inch provides sufficient flow and minimizes the risk of blockage, which can occur with smaller sizes, ensuring that the sight glass can provide a clear and accurate reading of the water level. Properly sized connections are essential for maintaining operational safety and efficiency in steam systems, as they help prevent issues that can arise from inadequate water levels, such as overheating or boiler failure.

While other sizes such as 1/4 inch, 3/4 inch, and 1 inch may be used in different contexts or applications, they do not reflect the standard minimum size typically required for sight glasses on low-pressure steam boilers.