In order to ensure the quality of the hose product, it is necessary to pass the uniform testing of the hose testing machine after the product leaves the factory, which needs to ensure that the pressure testing machine works normally and accurately. However, in the working process of the pressure testing machine, the phenomenon that the maximum load cannot be loaded often occurs. As a professional hydraulic pipe manufacturer, the main reasons for this phenomenon are summarized as follows.
1. Oil viscosity is low. When the oil supply valve returns to the oil pipe, there is oil flowing out. At this point, the oil of the appropriate viscosity should be replaced and, if necessary, measured with a viscometer.
2. The oil system leaks oil. The oil leakage of the oil circuit system generally appears at the connection of the buffer valve, the oil return valve, the oil delivery valve, the oil pump and the pipeline. If the screw is loose, tighten the screw. If the sealing oil ring and the sealing gasket are broken, it must be taken apart and replaced with a new one.
3. The fuel tank is not enough. When loaded to a certain load, the oil return valve of the oil supply valve has a sound, and there is little oil and bubbles. When the load can no longer rise, the return pipe has no oil to flow out. At this point, you should add oil to the test engine tank until you see that the oil level reaches half of the oil sight.
4. The belt that drives the oil pump is loose and slippery. After loading to a certain load, it can no longer rise, and the oil return valve has no oil flowing out, and the oil pump has no working sound. At this point, the motor fixing screw should be loosened, the position should be adjusted, the belt should be tightened, and the motor fixing screw should be tightened. If the belt is too deformed, you will have to replace it with a new one.
5. The oil supply valve has a low spring stiffness or a blocked plug cavity. Each load can only reach a certain load. When the load can no longer rise, the oil return to the oil return pipe is large. At this time, it is necessary to change the stabilizer spring with appropriate stiffness or clean the dirt.
6. The plunger of the oil pump is not compressed or the gap between the plunger and the plunger sleeve is large. After several consecutive loadings, the load reached is gradually reduced, and the oil return valve returning oil has no oil flowing out. At this point, the plunger sleeve cap should be tightened with a wrench or a new plunger and plunger sleeve should be replaced.
7. The oil pump plunger is rusted. During the loading process, when the oil return valve return oil is not continuous or fluctuates until a certain load can no longer rise, the oil return pipe has no oil flowing out. The plunger should be removed and re-polished.
8. The oil collector of the oil pump is not pressed against the pump body. Each load can only reach a certain load, and the load can no longer rise, and the oil return valve has no oil to flow out. At this time, the fixing screw at the rear end of the oil pump should be tightened with a wrench. If there is still a problem, remove the oil collector and add a gasket between the oil collector and the pump body.
9. The oil supply valve piston and piston sleeve are damaged. The load that can be achieved with each load is basically unchanged, and the oil delivery valve is noisy. When the load can no longer rise, the oil return to the oil return valve of the oil supply valve is large. Remove the grinding sleeve from the product and replace it if the damage is serious.
10. The gap between the oil supply valve damping needle and the orifice is too small. Each load can only reach a certain load. When the load can no longer rise, the oil return to the oil return pipe of the oil supply valve is large. At this point, the damper needle should be removed and the trowel should be properly removed along the axial direction of the damper needle.
11. The clearance between the working cylinder and the working piston is too large. As the load increases, the oil flows out of the gap of the working cylinder, and there is always oil flowing out of the oil return valve of the delivery valve. The working cylinder and piston should be replaced at this time.