What happens inside a hydraulic system when a seal fails?

What Happens When a Hydraulic Seal Fails?

Hydraulic systems are the heartbeat of numerous industries, driving everything from huge construction equipment to complex manufacturing machinery. They function under extreme pressure and rely on the delicate balance between fluid dynamics and precise engineering. What happens if the smallest of components, like a seal, fails to give way? Unfortunately, the answer can vary from minor flaws to a catastrophic failure of the system.

The Role of the Seal: A Guardian Against Leakage

Imagine the hydraulic network as a series of veins and arteries, with hydraulic fluid being its lifeblood. Seals are the key gatekeepers that prevent the vital fluid from leaving its route. They provide a solid separation between stationary and moving components, making sure that the pressure remains constant and that power is effectively transmitted.

There are a variety of seals, all designed for specific purposes or operating circumstances:

• The seals on the rod: Eliminate fluid loss within the piston rod.

• The piston seals stop the flow of fluid between the piston wall of the cylinder.

• Wipers Block external contaminants from getting into the cylinder.

• Static seals (O-rings, gaskets): Prevent leakage between moving parts.

The Cascade of Failure: What Happens When a Seal Breaks Down?

If a seal in the hydraulic system is damaged, it's not an isolated, single event. In fact, it can trigger an unintended chain reaction of consequences that could quickly destroy the whole system.

1. Loss of Pressure and Performance:

The immediate and obvious result of a failing seal is the reduction in hydraulic pressure. In the event that fluid escapes the system, it can no longer sustain or achieve the force needed for its intended use. This causes:

• Slow-moving: Actuators operate slowly or fight to move heavy objects.

• Lower lifting capacity: Equipment cannot lift the same amount as it would.

• Inaccurate positioning, Precision machinery ceases to make precise moves.

• Speedy cycles: Operations take longer, which reduces productivity.

Imagine a crane in a construction site trying to raise beams or a forklift that is unable to get its forks raised to the desired height. These are the direct result of pressure loss caused by seal failure.

2. Overheating and Fluid Degradation:

When the system is trying to make up for the loss of pressure and reduce the pressure, the hydraulic pump has to work harder, producing an excessive amount of heat. The elevated temperature has a variety of negative consequences:

• Accelerated degradation of fluids: Hydraulic fluid degrades more quickly, degrading its lubrication properties, increasing wear on the components.

• Seals that are damaged further: High temperatures can make the seals harder, crack or soften seals that remain, aggravating the issue.

• Viscosity reduced: The fluid becomes thinner, thereby reducing its capacity to hold pressure and maintain lubrication.

3. Contamination Ingress:

A damaged seal won't only let fluid out, but it can also allow contaminants to enter. If a seal intended to keep dirt and debris from the system breaks, dangerous particles can get into the fluid. These particles act as sandpaper, causing internal damage and speeding wear.

• Walls of the cylinder are scratched: This can lead to leakage and the possibility of scoring.

• Pump and valve components: Reducing their efficiency and life span.

• Filters that are clogged: Requiring more frequent replacement, which could lead to bypass of filters.

4. Component Wear and Damage:

The combination of lower lubrication process, higher temperatures, and contamination creates an ideal storm for increased wear on the most critical hydraulic components.

• Failure of the pump: The pump, working overtime in a polluted environment, is usually the first component to fail.

• Valves damaged: Spools and bores could be scored, which can lead to internal leakage and unsteady operation.

• Cylinder damage: Piston rods and barrels can become scratched or damaged, which requires expensive repair or replacement.

Here's an illustration of typical seals as well as how they are integrated into the hydraulic system. 

5. Environmental and Safety Hazards:

Fluid leaks are not just operational issues but also create health and safety hazards.

• Contamination from the environment: Fluids from hydraulic leaks can cause water and soil contamination, which can lead to costly cleaning.

• Slip dangers: Puddles of fluid can create hazardous working conditions, which increase the chance of falls and slips.

• Risk of fire: In some applications, leaks of hydraulic fluid could create a fire risk.

Preventing the Silent Killer: The Importance of Maintenance

The devastating consequences of a seal failure emphasize the importance of preventive maintenance.

• Regularly-scheduled checks: Routinely check for obvious leaks, changes in the performance of your system, or any unusual sounds.

• Analyzing fluids: Regularly analyze the hydraulic fluid to detect degradation, contamination, as well as wear and tear particles.

• Seal selection that is correct: Ensure the correct seals are chosen for the particular application, temperature, pressure, as well as the type of fluid.

• Proper Installation: Improper seal installation is the most common reason for premature failure.

• Control of contamination: Maintain clean hydraulic fluid by ensuring appropriate filtration and procedures.

A modest investment in maintaining your seals can help prevent costly repairs, cut down time, and ensure the safety and efficiency of your hydraulic system. Don't overlook the silent killer. Protect your seals and keep your hydraulics operating smoothly.