How does temperature affect hydraulic cylinders: Protecting hydraulic systems from extreme temperatures

Extreme temperatures can significantly shorten the service life of hydraulic systems and affect their effective operation. To protect the hydraulic cylinder and other system components from damage, it is necessary to pay attention to the influence of temperature on the viscosity of hydraulic oil.Extreme temperatures may cause a decline or complete loss of the capacity of hydraulic cylinders, component failures, and eventually damage the system, leading to inevitable hydraulic maintenance.

This article Outlines the potential risks of extreme temperatures for hydraulic oil and provides suggestions for preventing such damage.

How does low temperature affect hydraulic oil and hydraulic cylinders

Low temperatures can have various adverse effects on hydraulic cylinders:

Increased viscosity of hydraulic oil: An increase in the viscosity of hydraulic oil will reduce the flow rate of the oil, exerting pressure on the pump. Excessive force can lead to cavitation (the formation and rupture of bubbles), which in turn causes lubrication failure, corrosion, metal debris and system failure. Low-temperature hydraulic oil can also cause unstable operation of the system and accelerate the wear of other components.

Sealing performance decline: Low temperatures can make seals brittle and reduce their flexibility, leading to cracking or shrinkage and lowering their leak-proof capacity. If the damaged seals are not repaired or replaced, moisture, dirt and air will enter the hydraulic oil, causing system failure.

Intensified condensation: Excessive condensation can lead to corrosion inside the cylinder, accumulation of moisture in the system, and valve blockage, all of which will reduce the efficiency of the system.

Induced brittleness: At low temperatures, the metal components in the hydraulic cylinder become more brittle and are prone to cracking or breaking. The harder the component is, the faster it will be damaged. Continuous expansion and contraction can also cause fatigue of metal materials such as aluminium, steel and hydraulic hoses, which may lead to system failure.

The influence of high temperature on hydraulic cylinders

Heat is naturally generated when the hydraulic pump is in operation. But the temperature should not exceed 74°C (180°F).

Extremely high temperatures can have various adverse effects on the hydraulic system:

Seal failure: Seals, such as hydraulic cylinders, operate optimally within the range of 110 to 130°F. When the temperature exceeds its specification, multiple properties such as hardness, wear resistance, tear resistance and lubricity may change. These situations may lead to seal failure, causing oil leakage from the seals, system contamination and metal-to-metal contact, which may result in permanent damage to the cylinder components.

Oxidation intensification: At high temperatures, the oxidation of hydraulic oil can produce adverse by-products. The accumulation of these by-products (such as sludge and paint film) can clog hydraulic pipelines and valves, leading to a decline in efficiency and performance. In extreme cases, it may even cause the system to fail prematurely. For every 10 degrees Celsius increase in the temperature of the hydraulic oil, the rate of the chemical reaction doubles. Therefore, the higher the temperature of the hydraulic oil, the faster the oxidation rate.

Lubrication loss: High-temperature hydraulic cylinders will reduce the viscosity of the oil. After exceeding a certain temperature, the oil will no longer be able to effectively protect the components of the reciprocating hydraulic cylinder. Overheating of the oil will accelerate mechanical wear, leading to the frequent replacement of pumps and hydraulic cylinders

Precisely locate and alleviate the heat accumulation in the hydraulic system

The reasons for the overheating of the hydraulic system

Quickly identifying the causes of hydraulic cylinder overheating can prevent irreversible system damage.

Some of the most common causes of overheating in hydraulic pumps include:

Hydraulic oil contamination: If the hydraulic oil contains debris and dirt, contamination particles will accumulate and clog the system filter. If this happens, the pump must consume more energy to force the hydraulic oil to flow through the filter, thereby causing overheating.

Inflation: Air leakage at the seals and connections of the hydraulic system can allow air to enter, thereby creating bubbles in the oil. When these bubbles are compressed, heat is generated, causing the temperature to rise.

Low liquid level in the storage tank: A low liquid level in the storage tank of the hydraulic system leads to ineffective heat dissipation, resulting in rapid overheating and unstable pressure.

Heat exchanger blockage or damage: This component is crucial to the cooling system of the hydraulic pump. If it is clogged or damaged, it will not be able to properly discharge the heat inside the pump.

Flow regulator damage: If the flow regulator does not operate properly, the amount of fluid flowing through the system will be insufficient, resulting in inadequate lubrication and cooling, and thus causing the system to overheat.

Low pressure level: When the system pressure is too low, it cannot remove heat from the working components.

How to prevent the temperature of the hydraulic system from being too high

You can prevent the hydraulic cylinder equipment from malfunctioning by performing the following operations:

Use the correct hydraulic oil: Only use the hydraulic oil designed for your specific hydraulic system;

Keep the fluid clean and free from contamination: Replace the fluid regularly as recommended by the manufacturer.

Use a heat exchanger: A heat exchanger can help dissipate the heat in the hydraulic oil and prevent it from overheating.

Regularly check if there is any leakage in the system: Regularly inspect and repair any leakage immediately.

Do not overload the system: Always operate within its designed limits;

Use a cooling system: If your hydraulic system operates in a high-temperature environment, you may need a cooling system to help dissipate excessive heat.

Professional hydraulic system repair and maintenance services

Although the external environmental temperature cannot be controlled, regular inspection and maintenance can keep your hydraulic system in good working condition.

It is also very helpful to use the correct hydraulic oil and invest in a cooling system. By taking necessary measures to manage extreme temperatures, your hydraulic cylinders will remain in the best condition and reduce maintenance requirements.