Performance testing of rubber oil-resistant pipes: ensuring quality and safety

Before the rubber oil-resistant pipe is put into use, it must undergo rigorous performance testing to ensure its quality and safety and meet the needs of various industrial applications.
1. Oil resistance performance test
Oil resistance is one of the most important properties of rubber oil-resistant pipes, and its test methods are varied. A common method is to immerse the rubber oil-resistant pipe sample in a specific oil and test it under specified temperature and time conditions. For example, for rubber oil-resistant pipes used in the lubrication system of automobile engines, the sample can be immersed in the engine oil, and the temperature is set within the normal operating temperature range of the engine, such as 100-120°C, and the immersion time can be several days or even weeks.
During the immersion process, regularly observe the changes in the rubber oil-resistant pipe samples, including changes in appearance, weight, hardness, etc. In appearance, if swelling, cracking, discoloration, etc. appear on the rubber surface, it indicates that there may be problems with the oil resistance of the rubber. Weight changes can be measured by precision balances. The weight increase may be because the rubber absorbs oil, which may affect the physical properties and chemical stability of the rubber. Hardness changes are measured using a hardness tester. Abnormal changes in hardness may mean that the internal structure of the rubber has changed due to the erosion of the oil.
In addition, the oil resistance of rubber oil-resistant pipes can also be evaluated by chemical analysis methods. For example, analyzing the changes in the chemical composition of rubber after immersion, detecting whether there is a break in the rubber molecular chain or the generation of new chemicals, this information can provide a deeper understanding of the interaction between rubber and oil.

2. Pressure resistance test
The pressure resistance test is to determine the limit capacity and safety performance of rubber oil-resistant pipes when subjected to internal pressure. The test equipment is usually a hydraulic pressure tester, which seals one end of the rubber oil-resistant pipe and connects the other end to the hydraulic system of the pressure tester.
During the test, the hydraulic pressure is slowly increased, and measuring equipment such as pressure sensors and strain gauges are used to monitor the pressure in the oil pipe and the deformation of the oil pipe. The pressure gradually increases until the oil pipe fails, such as rupture or leakage. The pressure value at this time is recorded, which is the pressure resistance limit of the rubber oil-resistant pipe. For rubber oil-resistant pipes in different application fields, the pressure resistance requirements are different. For example, the rubber oil-resistant pipes in the automotive brake system need to withstand higher pressures, and generally require a pressure resistance of more than several MPa, while the rubber oil-resistant pipes in some ordinary industrial hydraulic systems have relatively low pressure resistance requirements.
In addition to the ultimate pressure test, fatigue pressure test is also required. In this test, the rubber oil-resistant pipe is repeatedly pressurized and depressurized within a certain range of pressure to simulate the pressure fluctuations in actual use. After multiple cycles, check whether the oil pipe has leakage, rupture or other performance degradation to evaluate the reliability of the oil pipe in a long-term pressure change environment.

3. High temperature performance test
Rubber oil-resistant pipes need to work in high temperature environments in many industrial applications, so high temperature performance testing is essential. The commonly used test method is to place the rubber oil-resistant pipe sample in a high temperature oven and heat it for a certain period of time under different high temperature conditions.
For example, the temperature can be gradually increased from room temperature to 200°C or even higher, staying at each temperature point for a certain period of time to observe the changes in the rubber oil-resistant pipe. High temperature may cause the rubber to soften, deform or lose elasticity, and these changes will affect the normal use of the oil pipe. The high temperature resistance of the rubber oil-resistant pipe can be evaluated by measuring the changes in the physical properties of the rubber before and after high temperature, such as tensile strength, elongation, hardness, etc. At the same time, it is also necessary to observe whether the rubber oil-resistant pipe has smoke, decomposition and other phenomena at high temperatures. These phenomena indicate that the rubber has poor high temperature resistance and may not work properly in high temperature environments.

4. Low temperature resistance test
In some industrial applications in cold areas or low temperature environments, the low temperature resistance of rubber oil-resistant pipes is crucial. Low temperature resistance tests are usually carried out in a low temperature box to cool the rubber oil-resistant pipe samples to a very low temperature, such as – 40°C or even lower.
In a low temperature environment, observe the flexibility and hardness changes of the rubber oil-resistant pipe. If the rubber becomes too rigid at low temperatures, it may cause the oil pipe to break easily when subjected to external force. Measuring the physical performance parameters of the rubber oil-resistant pipe at low temperatures and comparing them with the parameters at normal temperature can determine the performance changes of the rubber oil-resistant pipe in a low temperature environment, thereby evaluating whether it meets the requirements of low temperature applications.

Through these comprehensive performance tests, the safe and reliable use of rubber oil-resistant pipes in various complex industrial environments can be ensured, providing strong guarantees for industrial production and equipment operation.