What is the standard inlet size for the fire department inlet used to supply a standpipe system?

What is the standard inlet size for the fire department inlet used to supply a standpipe system?

• A. 2 in
• B. 2 1/2 in
• C. 3 in
• D. 4 in

Answer: (B)

The main idea is that the fire department inlet to a standpipe is standardized to match the common attack hose used by firefighters. The standard size is 2-1/2 inches because most fire departments deploy 2-1/2 inch hoses to connect to a standpipe’s inlet, ensuring quick, direct compatibility with minimal adapters. This size provides a practical balance between the flow needed to supply a standpipe and the weight and handling characteristics of the hose. While some high-volume or special installations may use larger inlets (such as 4 inches) to receive bigger supply lines, the typical and most widely used inlet size is 2-1/2 inches.

The main idea is that the fire department inlet to a standpipe is standardized to match the common attack hose used by firefighters. The standard size is 2-1/2 inches because most fire departments deploy 2-1/2 inch hoses to connect to a standpipe’s inlet, ensuring quick, direct compatibility with minimal adapters. This size provides a practical balance between the flow needed to supply a standpipe and the weight and handling characteristics of the hose. While some high-volume or special installations may use larger inlets (such as 4 inches) to receive bigger supply lines, the typical and most widely used inlet size is 2-1/2 inches.