A sign of hydraulic seal failure

After the hydraulic system has been tested and put into use, there will be a leak, generally there will be signs before the leak is not obvious, of course, in the real situation there are no signs and suddenly appear leakage, it is impossible to prevent and deal with in advance. If there are signs of leakage, it is necessary to observe and check frequently, and if found, the leak can be disposed of in advance.
Sign # 1 Sweating. It often breaks at the junction, or somewhere. Although the joint is shaken loose, although there are cracks at the crack, but not completely cracked, so the liquid does not leak, but only slowly permeate outward, so a slight oil or sweat phenomenon. Once the joint is further loosened and the crack is further deepened until it is cracked through, there will be leakage at the joint and the crack.
Abnormally high temperatures in Sign 2 May also be a sign prior to the leak. It may be caused by abnormal wear and heating of the seal, such as continuing to run, further wear of the seal, will produce leakage.
Symptom 3 When the hydraulic actuator is running, especially in slow operation, it stops and moves when it appears, such crawling phenomenon is caused by a variety of reasons, but one of the reasons is caused by uneven flow. When the speed is not very high, as long as there is leakage, the flow is not uniform, the operation of the cylinder will appear uneven phenomenon, then you can consider the existence of leakage.
Symptom 4 Hydraulic actuators, such as the movement of the piston rod of the hydraulic cylinder, may find that its full cylinder reflection is not the same, such as some strong light, some parts have signs such as strain marks. The former is that the piston is worn, and the latter is that the piston movement is strained by the hard particles, which will cause leakage over time.
Symptom 5 The oil supply of the pump is unchanged, the speed control valve and the throttle valve are placed in a fixed position, and the movement speed of the actuator such as the hydraulic cylinder is slowed down, which is also due to leakage and the effective flow rate is reduced.
Symptom 6 In the working process, the pump speed has not changed, and the load is constant, but the cylinder shows weakness in the actual work, which may also be caused by the leakage of insufficient pressure, which is also a sign of the leakage of the hydraulic system.
Symptom 7 When the hydraulic system is working, it smells bad, which may be the deterioration of the oil, or the odor released by aging, deterioration, chemical changes, etc. of the seal. That is, the sealing performance of the seal has begun to weaken and deteriorate, and the sealing function will then fail, resulting in leakage. Therefore, when the smell is bad, it may also be a sign of leakage.
Symptom 8 When the piston rod in the cylinder reciprocates, if there is a symptom of the oil ring on the piston rod, the sealing of the dust ring and the seal may not be coordinated and mutually restricted, and the leakage may occur in the long run.
Symptom 9 The working time of the hydraulic system is not very long, that is, the working time is not long, the hydraulic oil becomes cloudy, which means that the working environment is dusty and the oil has been polluted, which will accelerate the piston rod, the cylinder hole is easy to be pulled, and the seal is also subjected to serious wear, which will lead to leakage.
If the surface of the reciprocating piston rod of sign 10 is bruised, or the electroplating is found to be falling off, these are also one of the leaks.
Sign 11 If it is found that some sealing gaskets lose elasticity, or there are scratches, or there are cracks, especially the sealing rings that have been used for a long time are prone to these signs, so that they continue to be used again, there will be leaks.
Symptom 12 Sometimes in cleaning, disassembly, maintenance, it will be found that the seal is hardened, glowing, hand pressure cracks, deformation, elasticity is significantly reduced or disappeared, defects, expansion, contraction, softening and other phenomena, all indicate that the sealing effectiveness of these seals is weakened or even lost, and it is still used, it will leak. The above sealing phenomena are that the sealing effectiveness will be lost and leakage will occur.
The roughness of many rotary sealing shafts is too large or there are marks or scratches, the seal lip is cracked or tightened, the pressure is too high, the temperature is too high, the lack of oil dry friction, the invasion of dust particles, etc., are all signs of leakage.
In reality, the situation will be more complicated, the above listed hydraulic system leakage symptoms are only a small part, the others are still summarized by exploring in practice. In addition, we have to admit that in reality, there will be a sudden leak, and no signs have been found, which tells people that the leak is not completely detected by people, to improve the awareness of leakage prevention of the hydraulic system, and carefully focus on dealing with it, and do a good job in sealing.