Hydraulic Tubes Selected for Hydraulic Systems with Different Pressures

How to choose hydraulic tubes according to the pressure of the hydraulic system? First of all, the working pressure range of the hydraulic system should be clarified. This can be determined by checking the technical manual of the equipment, consulting the equipment manufacturer or conducting actual pressure tests. The pressure levels of hydraulic systems are generally divided into low pressure (usually less than 1.6MPa), medium pressure (1.6 - 16MPa), high pressure (16 - 32MPa) and ultra-high pressure (greater than 32MPa).

For example, the hydraulic brake system of a car generally belongs to a medium pressure system with a working pressure of about 8 - 12MPa; while the hydraulic system of a large die-casting machine may belong to a high pressure or ultra-high pressure system with a working pressure of 30 - 100MPa.

Low-pressure hydraulic system (less than 1.6MPa)

For such a low-pressure system, ordinary rubber hoses or thin-walled steel pipes can be selected.

1. Advantages of rubber hoses

Ordinary rubber hoses are relatively low in price, have good flexibility, and are easy to install and arrange. It can easily adapt to the shape and movement of the equipment. For example, in some simple hydraulic tools, such as manual hydraulic jacks, ordinary rubber hoses can meet the requirements.

2. Advantages of thin-walled steel pipes

Thin-walled steel pipes have certain strength and low cost, and are more suitable in some occasions where a more stable pipe shape is required (such as when the pipe does not want to bend excessively). Its internal surface is relatively smooth, which is conducive to the flow of hydraulic oil and reduces pressure loss.

Medium-pressure hydraulic system (1.6 - 16MPa)

It is recommended to use high-quality seamless steel pipes or multi-layer steel wire braided rubber hoses.

1. Advantages of seamless steel pipe

Seamless steel pipes have high strength, can withstand pressure in the medium pressure range, and have good temperature resistance and corrosion resistance. It is suitable for fixed hydraulic systems, such as hydraulic systems of general industrial machine tools. In some occasions where the pipe size accuracy is high, seamless steel pipes can also better meet the requirements because its outer diameter and inner diameter size accuracy are higher than those of seamed steel pipes.

2. Advantages of multi-layer steel wire braided rubber hose

Multi-layer steel wire braiding enhances the pressure resistance of the rubber hose, enabling it to work stably under medium pressure environments. This rubber hose also retains flexibility and is suitable for parts of the equipment with certain movement or vibration. For example, in the hydraulic control system of engineering machinery, multi-layer steel wire braided rubber hose can adapt well to various movements of the equipment when it is working.

High-pressure hydraulic system (16 - 32MPa)

Generally, thick-walled seamless steel pipes or steel wire braided rubber hoses with high reinforcement layer density are used.

1. Advantages of thick-walled seamless steel pipes

Thick-walled seamless steel pipes can withstand high pressure, and their strength and pressure resistance are the main selection criteria. This steel pipe is usually used in occasions with extremely high safety requirements, such as the hydraulic system of mining machinery, because once the hydraulic tube ruptures, it may cause serious safety accidents.

2. Advantages of steel wire braided rubber hoses with high reinforcement layer density

By increasing the density and quality of the steel wire braided layer, the pressure resistance of this rubber hose is greatly improved. It can adapt to high-pressure environments while ensuring a certain degree of flexibility. In some complex high-pressure hydraulic equipment, such as the high-pressure injection part of the injection molding machine, this rubber hose can easily connect various components and withstand the high pressure during the injection process.

Ultra-high pressure hydraulic system (greater than 32MPa)

It is necessary to select special high-strength hydraulic tubes, such as thick-walled alloy steel pipes or rubber hoses with multiple layers of high-strength reinforcement layers.

1. Advantages of thick-walled alloy steel pipes

Alloy steel pipes improve the strength and pressure resistance of materials by adding alloy elements. Thick-walled alloy steel pipes can withstand ultra-high pressure and are often used in aerospace equipment, large hydraulic presses and other fields with extremely high pressure requirements. For example, in the hydraulic control system of aerospace, thick-walled alloy steel pipes can ensure precise control of the system under ultra-high pressure.

2. Advantages of rubber hoses with multiple layers of high-strength reinforcement layers

The internal reinforcement layer of this rubber hose is made of high-strength material, and the pressure resistance is improved by special weaving or winding processes. It is suitable for some occasions that require both flexibility and ultra-high pressure bearing capacity. For example, in some special high-pressure test equipment, rubber hoses can easily connect the test device and the tested parts.

Summary

If you want to choose hydraulic tubes according to the pressure of the hydraulic system, you must first determine the pressure level of the hydraulic system, distinguish the pressure level of the hydraulic system, and select steel pipes of suitable materials. In addition to the above requirements, in order to ensure the safety and reliability of hydraulic tubes during use, a certain pressure safety factor should be considered when selecting hydraulic tubes. It is generally recommended to select hydraulic tubes with a rated pressure 1.2 - 1.5 times higher than the working pressure. For example, if the working pressure of the hydraulic system is 10MPa, it is more appropriate to select hydraulic tubes with a rated pressure of 12 - 15MPa. This can cope with pressure fluctuations and shocks that may occur in the hydraulic system, extend the service life of the hydraulic tube, and reduce the risk of leakage and damage.