In heavy-duty industries, machines need to lift massive loads safely. Standard cylinders can sometimes bend or leak under extreme pressure. To solve this, engineers use a simpler and stronger option: the plunger hydraulic cylinder (also called a ram cylinder or ram).

This guide explains how a ram cylinder works, its key formula, and why it fits heavy lifting jobs. We also show how Shellppon Hydraulic builds these robust tools for tough environments.

1. What is a Plunger Hydraulic Cylinder?

A plunger hydraulic cylinder is a single-acting hydraulic tool. In this design, a solid, wide piston rod (the plunger) bears all the pressure.

The system works in a simple way: hydraulic fluid pushes the plunger out, and an external force (like gravity or a spring) pushes it back in.

2. How the Structure Works

The best part of a plunger cylinder is its simple design. Standard cylinders use an internal piston head to divide the inside into two rooms.

A plunger cylinder has no internal piston head. Instead, the wide, solid rod itself receives the fluid pressure as it moves in and out of the single fluid chamber.

Core Movement and Force Analysis

• Going Out (Extension Stroke): Hydraulic fluid enters a single port at the bottom. This fluid pushes directly against the bottom area of the solid rod. You can calculate the lifting force with this simple formula:

  F = P x A

  (Here, F is the lifting force, P is the fluid pressure, and A is the cross-sectional area of the solid rod).

• Coming Back (Retraction Stroke): This tool is single-acting, so it does not use fluid pressure to pull the rod back. Instead, three natural methods push the rod down:<