Replacing the valve core in a 20-inch household gate valve involves several critical steps to ensure safety and functionality. First, shut off the water supply to the valve and drain the line to prevent water accumulation. Next, disconnect the supply lines connected to the valve body. Remove the retaining nut or bolts securing the valve body to the pipe. Extract the old valve core by lifting or twisting it out, ensuring no debris remains in the valve seat. Clean the valve seat thoroughly to guarantee a proper seal. Insert the new valve core, aligning it with the seat, and secure it with the retaining nut or bolts. Reconnect the supply lines, restore water pressure, and test the valve by opening and closing it to confirm functionality.

This process is essential due to the valve core’s role in controlling water flow and preventing leaks. A damaged or corroded core can lead to uncontrolled water discharge, property damage, or safety hazards. According to the American Water Works Association (AWWA), approximately 15% of water main failures in household systems are linked to valve issues, with improper maintenance contributing to 30% of these failures. Replacing the core promptly reduces water waste—each leaking valve can waste up to 10,000 gallons annually, as reported by the Environmental Protection Agency (EPA). Additionally, timely replacements extend valve lifespan by 20–30%, according to industry studies, avoiding costly emergency repairs. The valve core’s密封 (sealing) mechanism, if compromised, may allow pressure drops, risking pipe bursts. Data from the U.S. Infrastructure Report Card highlights that 24% of U.S. water systems face aging infrastructure, with valve replacements being a top priority for upgrades. Proper installation ensures compliance with building codes, which mandate functional valves to prevent cross-connection contamination. In summary, valve core replacement is a cost-effective, safety-critical maintenance task supported by empirical data on water loss, infrastructure longevity, and regulatory standards.