Cylinder Failures Due to Over pressurization

Hydraulic cylinders are designed to handle a specific working pressure. They also have a maximum pressure rating. This higher limit allows for short pressure spikes without damage.

However, when pressure exceeds this limit, problems occur. The cylinder may wear faster or fail immediately.

Why Over pressurization Happens

Hydraulic cylinders use steel and elastomer components. Each material has limits. When pressure exceeds those limits, parts begin to fail.

Controlling pressure is not only about pump settings. External forces also affect pressure inside the cylinder. These forces can create unexpected pressure spikes.

To prevent failure, you must understand how these spikes happen.

How Force Turns Into Pressure

Every hydraulic system uses an actuator. This can be a motor or a cylinder. The actuator moves a load at a certain speed.

Two key principles explain pressure behavior:

• Newton’s Law: Force increases with mass and velocity
• Pascal’s Law: Pressure spreads evenly through fluid

In simple terms, more force on the cylinder means more internal pressure.

Pressure and Load Relationship

Cylinder pressure depends on load and surface area. The formula is simple:

Pressure = Force ÷ Area

If the load increases, pressure also increases.

Larger cylinders can handle more force at the same pressure. However, sudden changes in force still create spikes.

Real-World Example

Imagine a wheel loader rated at 30,000 pounds with a system pressure of 3000 PSI.

At full load, the cylinder operates at 3000 PSI.

Now consider rough terrain. The load begins to bounce. This movement increases velocity and force.

As a result, pressure spikes occur. These spikes can reach 4000 PSI or more.

If speed increases, the problem gets worse. In extreme cases, pressure can reach 2–3 times the working limit. That means 6000 to 9000 PSI.

At that level, seals and steel components can fail quickly.

Built-In Protection

Manufacturers often include safety features. These may include:

• Port relief valves
• Pressure control systems
• Service safety factors

These features help absorb pressure spikes. They reduce the risk of sudden failure.

However, if these systems fail, damage can still occur.

Preventing Cylinder Failure

To reduce overpressurization risks:

Operate equipment within rated limits
Avoid excessive speed on rough terrain
Maintain pressure relief systems
Inspect valves and components regularly

Most importantly, always investigate failures. Finding the root cause helps prevent repeat issues.

Expert Support

RHK Hydraulic Cylinder Services Inc. provides expert support for all cylinder types. This includes both single-acting and double-acting systems.

From manufacturing to repair and rebuilds, our team helps keep your equipment running reliably.

Contact us today to learn more.