Which device is used on a sewage ejector discharge line to prevent backflow into the building?

Which device is used on a sewage ejector discharge line to prevent backflow into the building?

• A. Check Valve
• B. Gate Valve
• C. Ball Valve
• D. Stop Valve

Answer: (A)

Backflow protection on a sewage ejector discharge line is provided by a check valve. It allows wastewater to flow away from the building but automatically seals if flow tries to reverse, preventing sewer water or gas from backing up into the structure. The valve uses a movable element that is pushed open by forward flow and closes when reverse pressure occurs, so it responds automatically without manual action. Other shut‑off valves, like gate, ball, or stop valves, are designed to start or stop flow and don’t inherently prevent backflow; they can fail to block reverse pressure and aren’t suited for protecting the building from sewer backups. In practice, a check valve (often a swing or disk type) is installed on the discharge line downstream of the pump to provide this protection.

Backflow protection on a sewage ejector discharge line is provided by a check valve. It allows wastewater to flow away from the building but automatically seals if flow tries to reverse, preventing sewer water or gas from backing up into the structure. The valve uses a movable element that is pushed open by forward flow and closes when reverse pressure occurs, so it responds automatically without manual action. Other shut‑off valves, like gate, ball, or stop valves, are designed to start or stop flow and don’t inherently prevent backflow; they can fail to block reverse pressure and aren’t suited for protecting the building from sewer backups. In practice, a check valve (often a swing or disk type) is installed on the discharge line downstream of the pump to provide this protection.