Which valve on a makeup water line reduces pressure?

• A. Hand valve
• B. Pressure reducing valve
• C. Gate valve
• D. Ball valve

Answer: (B)

In a makeup water line, you want to control the pressure that enters the system. The device that does this is a pressure reducing valve. It automatically lowers the incoming water pressure to a set, lower downstream pressure and maintains that level even as the supply varies. If the upstream pressure is high, the valve trims back to keep the downstream pressure steady; if demand drops and downstream pressure falls, the valve opens more to restore the setpoint. Hand valves are manual shutoff or throttling devices without automatic pressure control. Gate valves and ball valves are designed mainly for on/off isolation (and occasional manual throttling) rather than maintaining a regulated downstream pressure. So the valve that reduces pressure on a makeup line is the pressure reducing valve.