Characteristics and uses of hydraulic hoses. Precautions for using hydraulic hoses

Hydraulic hose equipment medium temperature oil -40 ° C to 100 ° C; Air temperature ranges from -30 degrees to 50 degrees,; Water temperature ranges from -0 degrees to 80 degrees. Hydraulic hose media is used for hydraulic power transmission or conveying high-pressure media such as water, gas, oil, etc., to ensure the circulation of liquids and the transfer of liquid energy.

The standards commonly used in domestic and foreign trade for hydraulic hoses include DIN, SAE, ISO, and GB/T standards; The standards for steel wire braided hydraulic hoses are: DIN EN 853, SAE J517, GB/T 3683-2011, ISO1436; The standards for wire wound hydraulic hoses are DIN EN 856, SAE J517, GB/T 10544-2003, and ISO3862. The hydraulic hose models and specifications are 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 32, 34, 40, 42..., and their joints are matched with them. They are connected with metric fine thread or imperial pipe thread, and there are sealing threads and non sealing threads. Characteristics and uses of hydraulic hoses: 1. The hose is made of special synthetic rubber, which has excellent oil resistance, heat resistance, and aging resistance. 2. The tube body is tightly combined, soft to use, and has minimal deformation under pressure. 3. Rubber hoses have excellent resistance to bending and fatigue. 4. The rubber hose has high pressure bearing capacity and superior pulse performance.

The hydraulic hose products are mainly used for mine hydraulic supports, oilfield development, suitable for engineering construction, lifting and transportation, metallurgical forging, mining equipment, ships, injection molding machinery, agricultural machinery, various machine tools, and the transportation of petroleum based (such as mineral oil, soluble oil, hydraulic oil, fuel oil, lubricating oil) and water-based liquids (such as emulsions, oil-water emulsions, water) with certain pressure (high pressure) and temperature in mechanized and automated hydraulic systems of various industrial sectors, as well as liquid transmission. The maximum working pressure resistance can reach 60MPa. Precautions for hydraulic hoses: Inner diameter of the hose. 2、 Attention should be paid to the following matters in the use and design of rubber hoses: 1. The bending radius of rubber hoses should not be too small, generally not less than the value specified in the "Technical Characteristics of Hydraulic Hose Assemblies". The connection between the rubber hose assembly and the pipe joint should have a straight section, and the length of this section should not be less than twice the outer diameter of the pipe. 2. The length of the hose assembly should take into account that the hose will undergo shrinkage deformation after being filled with pressure oil, with a general shrinkage of 3-4% of the pipe length. Therefore, when installing the hose assembly, it is not allowed to be in a taut state. 3. The rubber hose assembly should be installed to ensure that no twisting deformation occurs. The joint axis of the hose should be placed as close to the plane of motion as possible to avoid damage to the hose when both ends move towards each other. 4. Rubber hoses should avoid contact and friction with sharp corners on machinery to prevent damage to the pipes. To ensure the safe and reliable use of the hydraulic hose assembly, special attention should be paid to the following matters. 1. Pressure: The working pressure specified for the hose should generally not be less than the maximum system pressure, and is only allowed to be increased by 20% in infrequent use; For those who use frequently and frequently bend and twist, it should be reduced by 40%. If the impact pressure of the system is higher than the specified working pressure of the hose, it not only reduces the service life of the hydraulic hose, but may also lead to personal and equipment accidents. 2. Temperature: The fluid temperature and ambient temperature, whether stable or instantaneous, must not exceed the temperature resistance limit of the hose. Temperatures lower or higher than the recommended temperature of the hose can reduce hose performance, cause hose damage, and lead to leakage. 3. Fluid compatibility: The fluid in the hose should comply with the regulations specified in the "purpose" of the product sample. Exceeding the regulations cannot guarantee the service life and safety of the hose. 4. Appropriate end connection: Nut connection is widely used due to its convenience and low cost, but in cases of high vibration, nut loosening should be fully considered and flange connection should be adopted. Hydraulic hose connection method 1. Card sleeve joint connection - pressure range: 250-800 Bar; Applicable steel pipe size range: 4-42mm; applicable materials: carbon steel and stainless steel.

The sleeve type pipe joint consists of three parts: the joint body, the sleeve, and the nut. When the card sleeve and nut sleeve are inserted into the joint body on the steel pipe and the nut is tightened, the outer side of the front end of the card sleeve is in contact with the conical surface of the joint body, and the inner blade is evenly bitten into the seamless steel pipe, forming an effective seal. Advantages: Widely applicable and mature; Relatively low-priced components; No special machine is required. Disadvantage: Only suitable for pipeline connections below 42mm; Not applicable to thin-walled pipes; Large installation space and torque are required during installation; Not suitable for working conditions with high safety requirements; Cannot be used for working conditions with strong vibrations, impacts, and pulses. 2. JIC37 degree connector connection - pressure range: 420 Bar (250 Bar, 100 Bar); Applicable steel pipe size range: 6-38mm; applicable materials: carbon steel, stainless steel, brass, copper alloy, etc. The JIC37 degree joint connection consists of three parts: joint body, bushing, and nut. After the liner and nut are inserted into the steel pipe, the expansion device is used to expand the end of the steel pipe and form it. Then, the joint body is tightened with the nut, and the rigid seal and O-ring seal are achieved through the conical contact surface.

Advantages: Widely applicable and mature; Wide range of applicable materials; Easy and convenient installation; Repeatable disassembly and assembly. Disadvantage: Only suitable for pipeline connections below 38mm; Low nominal pressure (excluding DNV standards); Not applicable to thick walled pipes; Need to expand the tail end of the equipment for molding. 3. End forming connection (Walform) - pressure range: 250-800 Bar; Applicable steel pipe size range: 4-42mm; applicable materials: carbon steel, stainless steel, copper alloy, etc. Walform connection is an alternative connection method for card sleeve connectors. After inserting the female sleeve into the steel pipe, the forming equipment is used to automatically extrude and shape the end of the steel pipe. After installing the sealing ring, the joint body and nut are tightened, and the joint body and forming surface are rigidly sealed and sealed with the sealing ring.

Advantages: Low torque and safe installation; The production process is fast and simple; Advanced technology without leakage; Repeatable disassembly and assembly. Disadvantage: Only suitable for pipeline connections below 42mm; Need to shape the tail end of the molding equipment. 4. Socket welding connection - pressure range: 420 Bar (only applicable to small pipe diameters); Applicable steel pipe size range: 6-150 mm; applicable materials: carbon steel and stainless steel. Socket welding connection is to insert the pipeline into the valve body for welding, and after forming, it has a similar appearance to the internal thread connection. Advantages: Widely applicable; Low component prices; Advanced technology without leakage; It is a simple connection method for low-voltage systems. Disadvantage: Requires skilled welders; Welding equipment, good ventilation environment, and fire prevention measures are required; Special cleaning and anti-corruption measures are required; It can lead to environmental pollution. 5. Welding connection - pressure range: 500 Bar (only applicable to small pipe diameters); Applicable steel pipe size range: 6-608 mm; applicable materials: carbon steel and stainless steel. There are butt welded flange connections and butt welded joint connections. Advantages: Widely applicable; Low component prices; Advanced technology without leakage; Tube to tube connection is simple. Disadvantage: Requires skilled welders; Welding equipment, good ventilation environment, and fire prevention measures are required; Special cleaning and anti-corruption measures are required; It can lead to environmental pollution.