Underground mains and lead-in connections shall be thoroughly flushed before connection to the system piping. True or False?

Underground mains and lead-in connections shall be thoroughly flushed before connection to the system piping. True or False?

• A. True
• B. False
• C. Only if required by local code
• D. Not applicable

Answer: (A)

The statement is true. Flushing underground mains and lead-in connections before they are tied into the system piping is required to remove debris and contaminants that can accumulate during trenching, installation, or fabrication. This cleaning helps prevent clogging of small passages, strainers, and the foam-water proportioning components, and it ensures the system will perform reliably when put into service. It isn’t conditional on local codes or a no-ops exception; the practice is a standard installation step to protect system integrity and foam performance.

The statement is true. Flushing underground mains and lead-in connections before they are tied into the system piping is required to remove debris and contaminants that can accumulate during trenching, installation, or fabrication. This cleaning helps prevent clogging of small passages, strainers, and the foam-water proportioning components, and it ensures the system will perform reliably when put into service. It isn’t conditional on local codes or a no-ops exception; the practice is a standard installation step to protect system integrity and foam performance.