Figure 3-22. - Hydraulic pressure regulator.

Figure 3-23. - Spring-loaded pressure-reducing valve.

movable element have equal areas. This type of movable element is frequently referred to as a plunger. The most common ram-type cylinders are the single-(fig. 3-28) and double-acting (fig. 3-29).

The ram-type actuator is primarily used to push, rather than pull. Some applications require simply a flat surface on the external part of the ram for pushing or lifting the unit to be operated. Other applications require some mechanical means of attachment, such as a clevis or eyebolt. The design of ram-type cylinders varies in many other respects to satisfy the requirements of different applications.

Figure 3-24. - Counterbalance valve.