Answer :
Final answer:
The primary protective device for a positive displacement pump is the relief valve, which protects the pump and system from over-pressurization by diverting excess flow.
Explanation:
The primary protective device for a positive displacement pump is the relief valve. Positive displacement pumps generate a fixed amount of flow through the mechanical contraction and expansion of a flexible diaphragm or by the movement of gear, screw, or piston. Since these pumps are capable of developing high pressures, a relief valve is essential to prevent over-pressurization and potential damage to the pump or the piping system. It works by opening at a set pressure limit and allows excess flow to be diverted, thus protecting the pump and the system it is a part of.
