How long does it take to flush headers?

• A. 15 seconds
• B. 45 seconds
• C. 60 seconds
• D. 30 seconds

Answer: (D)

Purging headers by flushing is about pushing air out of the piping trunk so the header is filled with water and ready for use. When you start the flush, water flow from the supply must travel through the header and out the discharge, carrying any trapped air with it until the line runs clean and full.

Thirty seconds is the standard duration because it reliably displaces air from typical shipboard headers without wasting time. Too short a flush may leave air pockets that delay pressurization or create air slugs during use. A longer flush doesn’t significantly improve the purge for this purpose and just adds unnecessary delay.