Arizona Plumbing Practice Exam

What must be installed on the discharge pipe of a pump in a sump pit?

1. Only a check valve

2. A check valve and full open valve

3. A surge tank

4. A timer switch

The correct answer is: A check valve and full open valve

The installation of a check valve and a full open valve on the discharge pipe of a pump in a sump pit is essential for proper system operation. The check valve prevents backflow of water into the sump pit when the pump is not in operation, which helps maintain the water level and protects the pump from potential damage due to repeated cycling. This valve essentially allows water to flow in one direction—out of the sump pit—while preventing it from returning, thus ensuring efficiency and protecting against overflow. In addition to the check valve, a full open valve is also required. This valve allows for complete control over the water flow from the pump, enabling the system to be shut off for maintenance or emergency situations without causing any disruption or backflow issues. Its installation is important in systems where manual control or isolation of the pump is needed for routine checks and repairs. The combination of these two types of valves ensures effective operation and longevity of the sump pump system, making it crucial for managing water discharge safely and efficiently. Other options like a surge tank or timer switch do not directly address the immediate need for backflow prevention and flow control in a sump pit system.