Function of a check valve on a pump discharge and where installed?

Function of a check valve on a pump discharge and where installed?

• A. To prevent reverse flow and protect the pump; installed on the suction side.
• B. To prevent reverse flow and protect the pump; installed on the discharge side close to the pump.
• C. To regulate pressure; installed near valve manifold.
• D. To vent air; installed at high point.

Answer: (C)

The main idea is that a check valve on the pump discharge exists to stop water from flowing backward toward the pump when the pump stops or pressure drops in the discharge line. By placing it on the discharge side, as close to the pump as practical, the valve shuts quickly and blocks any reverse flow, which helps keep the pump primed, reduces water hammer, and protects the pump from backflow damage. It isn’t used to regulate or set system pressure—that role belongs to a pressure-regulating or relief device—and it isn’t an air-vent device, which releases trapped air at high points. If the valve is installed far from the pump, backflow can bypass the valve or priming can be compromised, so proximity to the pump is important for effective protection.

The main idea is that a check valve on the pump discharge exists to stop water from flowing backward toward the pump when the pump stops or pressure drops in the discharge line. By placing it on the discharge side, as close to the pump as practical, the valve shuts quickly and blocks any reverse flow, which helps keep the pump primed, reduces water hammer, and protects the pump from backflow damage. It isn’t used to regulate or set system pressure—that role belongs to a pressure-regulating or relief device—and it isn’t an air-vent device, which releases trapped air at high points. If the valve is installed far from the pump, backflow can bypass the valve or priming can be compromised, so proximity to the pump is important for effective protection.