What is the maximum size for a blow off used on a high pressure boiler with less than 100 square feet of heating surface?

The maximum size for a blow-off connection on a high-pressure boiler with less than 100 square feet of heating surface is 3/4 inch. This specification is based on safety and efficiency standards within the boiler operations.

A blow-off valve is used to remove sediment and sludge from the boiler that can accumulate over time. If the diameter of the blow-off connection is excessively large, it could potentially lead to a rapid loss of water and pressure during operation. The 3/4 inch size strikes a balance between effectively removing sediment while still maintaining operational safety.

The codes and standards governing boiler operations often dictate these sizes to prevent issues that could arise from improper blow-off size, such as water hammer or inadequate removal of sludge, which could lead to boiler efficiency problems or even damage. Understanding these specifications helps ensure safe and effective boiler operation.