1.Classification of automobile air-conditioning pipes
Automobile air-conditioning pipelines are like the “ribs” of the air-conditioning system, which make the relevant parts scattered inside the car body closely connected in an orderly manner, and can also transfer energy to each part to ensure its normal operation.
It is well known that the most famous brand in the air-conditioning hose is Good year, and the name is Galaxy in the Chinese market. National brand-Cheaper than GALAXY to compete in the market, but the quality is also good for the aftermarket.
As a professional auto ac hose supplier & manufacturers, we provide stable quality and competitive prices automotive ac hose for you.
1.1According to the state of refrigerant
Gaseous tube: The refrigerant in the pipeline is gaseous;
Liquid tube: the refrigerant in the pipeline is liquid;
1.2Classified by pressure
High-pressure pipe: the automobile air-conditioning pipe from the compressor to the expansion valve;
Low-pressure pipe: the automobile air-conditioning pipe from the expansion valve to the compressor;
1.3Classified by structure
Hebei Ala Technology Co., Ltd. is divided into the following 3 models according to the structure and thickness of the hose
Structure: inner rubber layer, shielding layer, middle rubber layer, reinforcement layer, outer rubber layer.
Classification according to the thickness of the inner and outer walls of the pipe: A10、A20, 4826、4890
Structure: tube, buffer, reinforcement, cover
Classification according to the thickness of the inner and outer walls of the pipe: Bridgestone size、4860 Size、Transport refrigeration
Structure: inner resin layer, Isolation layer, inner rubber layer, reinforcement layer, intermediate rubber layer, reinforcement layer, outer rubber layer.
Classification according to the thickness of the inner and outer walls of the pipe: 4826 Size、4890 Size、Bridgestone Size、4860 Size
Note: Above Specification Just for your reference. We can produce the OEM Size for you
- Standard: SAE J2064
- Certificate: ISOTS 16949:2009
- Application Temperature: -40C ~ +135’C
- Refrigerant: R134a, R12
- Resistance: R134a、R12、R404a、1234yf refrigerant resistance, Low permeability, Pulse-resistance, Aging resistance, Ozone resistance, Shock resistance.
3.Inspection method of hose material performance
Commonly used rubber hose material performance tests include appearance size measurement, hydraulic test, low temperature bending test, liquid wall penetration test, durability test, fatigue test, ozone aging test, etc.
Usually, the inner rubber should be selected according to the heat resistance and the ability to withstand the transmission liquid, while the outer rubber needs to be heat resistant, ozone resistant and have good adhesion to the inner rubber.
3.1 Appearance size of hose
Hose size measurement inner diameter outer diameter reinforced layer outer diameter bi-thickness inner and outer layer rubber thickness assembly inner diameter, the new national standard and ISO increase the length and measuring point mark, stipulate the hose without pipe joints and various pipe joints Length measurement method.
3.2 Hydraulic test
3.2.1Verification pressure test:
Inspect whether the hose and assembly have leakage, deformation, and damage under the verification pressure for the 30s-60s.
3.2.2compression deformation test:
Keep it under the specified pressure (working pressure verification pressure or other pressure lower than the verification pressure) for 1 minute, and measure the change in the length and outer diameter of the hose as well as the torsion angle and bend.
3.2.3Burst pressure test:
Measure the pressure when the hose bursts under the specified pressure increase speed.
Store at a static pressure of 70% of the minimum burst pressure for 5 minutes, and repeat once to check for leakage or damage. Since the test often uses water and the viscosity of the liquid used is different, the burst pressure and leakage pressure measured at room temperature may be slightly lower.
(Usually, the working pressure of the hose design is the maximum pressure available. The pressure of the non-destructive test to verify the firmness of the hose is called the verification pressure, which is usually 1.5-2 times the working pressure. The pressure when the hose bursts is called blasting The pressure is 3-10 times the working pressure.)
3.3 Low temperature bending test
3.3.1Low temperature rigidity:
The hose is clamped on a torsion wheel with a diameter of 12 times the inner diameter of the hose. After being parked at a low temperature for 6 hours, the ratio of the torque measured when it is twisted by 180° in 12 seconds to the torque measured at standard temperature.
3.3.2Low temperature bending:
The hose is clamped on a torsion wheel with a diameter of 12 times the inner diameter of the hose. After being parked at a low temperature for 24 hours, the hose is twisted 180° within 10 seconds to check whether the inner and outer rubber is brittle and damaged.
The simplest test for measuring the low-temperature brittleness of a hose is to bend the sample at a low temperature by 90° or to freeze a section of the hose and compress it to see if it is brittle or not. Another method is to use a heavy hammer of a certain weight to fall freely and impact the sample to see if it is brittle. Whether the sample is brittle.
The bending test measures the ratio of the minimum outer diameter of the bent part to the outer diameter before bending, the passing capacity of the steel ball, and the bending force when the hose is pressurized after bending the hose to a certain degree.
3.4 Liquid wall penetration test
Under normal pressure, connect the hose to a container filled with a certain liquid and seal the nozzle of the container, place the test device horizontally, and then regularly weigh the quality change of the entire test device caused by the liquid permeating through the hose to find out The penetration rate of the liquid.
Apply an air pressure of 50kPa on the test liquid, release the pressure after a certain period of time, and measure the volume of the liquid reduced.
3.5 Durability test of hose
The durability test of the hose can reflect the actual performance and service life of the hose
Put the hose in an oven, and measure the changes in various properties of the hose after aging after a certain period of time, or wrap the hose on a cylinder, aging in the oven for a period of time, then take it out and straighten it to see if cracks occur.
3.6 Fatigue test of hose
Fatigue life test When the automobile hose is used, it must withstand the long-term effects of mechanical vibration, external environment, and internal medium
In the rotary fatigue test, the two ends of the rubber tube are installed on parallel non-moving and movable horizontal rods. The two ends of the movable rod are connected to the turntable. The loading speed drives one end of the rubber tube in the vertical direction at a speed of 800r/min. Make a circular rotation to seal the joint of the movable end, connect the non-moving end to the hydraulic source, apply a certain pressure, and record the time of leakage and damage.
Flexure-free hydraulic impulse test. Bend the sample by 90° or 180°. Apply medium pressure, pulse frequency, liquid temperature, and ambient temperature according to the use of the hose until the specified number of pulse cycles or until leakage and damage occur. Record whether it is damaged or not. The number of failures.
3.7 Ozone aging test of hose
The test under the static tensile condition of the ozone aging test of the hose is generally to cut the hose into a long sample and stretch it by 20% or bend it into a ring or fix the hose on a cylinder that can stretch the hose by 120%, or directly The hose is bent into a semicircular ring and wound on a mandrel with a diameter of 120% of the inner diameter of the hose. After a certain period of time at a certain ozone concentration, observe the cracking of the hose. The surface cracking test conducted in the atmosphere is a low-concentration ozone test, and the method is similar. In the test of the brake hose, and ozone resistance test of the hose under dynamic conditions was designed. One end of the hose was fixed, and the other end moved relative to the fixed end at a frequency of 0.3 Hz. After a certain period of time, the hose was checked for cracks.
(Usually, the concentration of ozone used in the test is 25~200pphm. The ozone resistance of rubber can be divided into three grades:
50~500pphm natural rubber, nitrile rubber, styrene-butadiene rubber, butadiene rubber, and isoprene rubber.
1000~2000pphm neoprene and butyl rubber.
Ethylene propylene rubber, chlorosulfonated polyethylene, chlorohydrin rubber, polyurethane, silicone rubber, and fluorine rubber over 100pphm.