High pressure diaphragm pumps utilize which fluid to activate them?

High-pressure diaphragm pumps are designed to operate using hydraulic fluid in most applications. Hydraulic fluid serves as the means to transfer energy within the pump, facilitating the movement of the diaphragm and, thus, the pumping action. This fluid is typically incompressible, which allows for precisely controlled movements and high-pressure applications.

While it is true that other fluids like air and steam can theoretically be used in certain types of diaphragm pumps, they are not standard for high-pressure applications. Steam is typically not suitable for high-pressure diaphragm pumps as it can lead to challenges such as condensation and corrosion of the internal components. Air, while used in pneumatic diaphragm pumps, does not provide the same level of control and efficiency in high-pressure scenarios as hydraulic fluid does.

The correct answer reflects the most common and practical application in the context of high-pressure diaphragm pumps, making hydraulic fluid the primary activation fluid.