Methods in Internal Leakage Detection of Hydraulic Components

Leakage refers to the loss of pressure oil flow caused by wear or seal failure of a component or a joint or a section of piping in a hydraulic system or a broken oil pipe. Leakage leads to a drop in system operating pressure, malfunction of the actuating element, or even can not work properly. Leakage is divided into external leakage and internal leakage, external leakage can generally be determined by the appearance of the inspection whether the leak, the fault is also relatively easy to deal with. Internal leakage appearance inspection is not possible, only through testing to determine whether the leak or the extent of leakage. More applicable detection is the application of a simple in situ detector or the use of a simple test to determine whether the hydraulic components leak. The former can achieve approximate quantitative detection, the latter qualitative detection. In addition, some hydraulic components can only use testing equipment to determine whether the leak or the degree of leakage, such as hydraulic pumps and hydraulic motors and other components, while some hydraulic components can also be used without testing equipment only through a simple test to determine whether the leak. For example, control valves, hydraulic cylinders and other components.

Hydraulic Cylinder Internal Leakage Detection

Do not use the detector, do not need to disassemble the hydraulic cylinder, in the equipment site, in situ check the hydraulic cylinder piston seal sealing effect.

Start the vehicle in situ, preheat the oil tank, check the pressure of "water oil circuit" and adjust it to 10Mpa, when the oil temperature reaches normal working temperature, manipulate the electromagnetic reversing valve 3 to make 1YT charged, the hydraulic cylinder rodless cavity is fed with oil, after the piston stops moving, make the electromagnetic reversing valve 3 disconnected. Disconnect the hydraulic cylinder 5's rod cavity connecting oil pipe at the joint, first plug the oil pipe with a wire plug, then connect a small section of hose to the hydraulic cylinder pipe joint, drain the remaining oil in the hydraulic cylinder rod cavity. Install a measuring cup and put the other end of the hose into the cup. Then manipulate the solenoid valve 3 again to make 1YT charged, while the stopwatch timing, observe the oil dripping, when the oil level reaches the maximum capacity of the measuring cup in line, record the time used. Then the leakage amount L (mI/min) can be calculated. If the above test is not required to quantify, but only to check whether there is leakage, it can be determined according to the observed oil dripping and reference to the equipment that can work normally.

Directional Control Valve Internal Leakage Detection

The structure of the directional control valve spool seals the inlet and outlet ports can be checked for internal leakage without removing them. Check first loosen the outlet joint, observe the fluid flow at the joint to determine whether the internal leakage. If the leakage flow is greater than the drip state, the valve can be suspected of internal leakage, and then removed from the system for further inspection and maintenance.

Leakage Detection Inside the Liquid-Controlled Check Valve

The liquid-controlled check valve is often used in the hydraulic system for pressure-holding, locking, so its tightness requirements are more stringent. Vehicle in situ start, tank warm-up, check the "water oil circuit" pressure, and adjust to 10Mpa, wait for the oil temperature to reach normal working temperature, manipulate the electromagnetic reversing valve 3 to make 2YT charged, hydraulic cylinder rodless cavity into the oil, after the piston stops moving, so that the electromagnetic reversing valve 3 disconnection locking hydraulic cylinder. The liquid-controlled check valve 5 into the oil circuit at the joint disconnected, with a silk plug at A with a silk plug to block the oil pipe, observe the liquid-controlled check valve 5 into the oil circuit at the disconnected oil dripping, such as leakage more than 34 drops per minute, can be identified as a leak, need to repair or replace. If you check the leakage condition of the liquid-controlled check valve 6, disconnect its oil inlet road, observe the oil dripping.