Technician A says that the presence check valve should hold system pressure for at least five minutes after the pump is shut off. Technician B says that a defective check valve could cause long cranking time. Which technician is correct?
A) Technician A. B) Technician B. C) Both technicians. D) Neither technician.

The correct answer is: D) Neither technician.

Explanation:

Check valves, also known as unidirectional valves, check valves or single-flow valves, completely close the passage of a circulating fluid while allowing free fluid on the opposite side. Its main use is in pipes that are attached to pumping systems to prevent the pump from working in a vacuum.

They are used when it is intended to keep a pipeline in service and put the power to discharge. The flow of the fluid that is directed from the inlet orifice to the one of use has the free passage, while in the opposite direction it is blocked.

They are widely used in pipes connected to pumping systems to prevent water hammering, mainly in the discharge line of the pump.

the bal will not change its velocity.