California ICC UST Service Technician Practice Exam

In a suction system, the check valve should be located:

1. Below ground

2. At the tank

3. Above grade and close to the pumping unit

4. At the dispenser

The correct answer is: Above grade and close to the pumping unit

In a suction system, placing the check valve above grade and close to the pumping unit is advantageous for several reasons. Firstly, locating the check valve above grade allows for easier access and maintenance. If issues arise, technicians can quickly inspect or replace the valve without needing to dig underground, which can be time-consuming and complicates repairs. Secondly, positioning the check valve near the pumping unit helps maintain proper pump functionality. The check valve's primary role is to prevent backflow and ensure that the liquid remains in the suction line when the pump is off. When the check valve is situated close to the pump, it is more effective at preventing the liquid from draining back into the tank after the pump has stopped, thus maintaining the prime in the suction line. Additionally, having the check valve above grade reduces the risk of corrosion and damage that can occur in underground installations due to moisture, soil pressure, or chemical exposure. In contrast, placing the check valve at the tank or below ground could hinder maintenance and increase the risk of system failure due to backflow or improper priming, while situating it at the dispenser might not effectively protect the pump in the same way. Therefore, the key considerations of accessibility, functionality, and durability make the chosen location for