| Nos. | Factor Of Insecurity | Produce Cause | Solution Methods |
| 1 | Leakage Between In Valve Seat And Valve Body | 1.Wear and ageing of seal. 2.Roughness and planeness of fitting surface are not eligibility | 1.Replacing the seal 2.Strict control quality of manufacture |
| 2 | Control Mechanism Of Hydraulic Valve Is Failure | 1.Voltage is differ in fitting of electromagnet 2.Alternating current and direct current are reversal in fitting of electromagnet | 1.Spiking discipline of procedure fitting 2.Strict control procedure and technique in fitting. |
| 3 | Hydraulic Valve Can Not Normal Working | 1. Valve plug have burrs or process precision is not eligibility. 2.Within leakage is superscale 3.Oil circuit system is leakage oil, valve have outer leakage | 1.Strict control quality of manufacture. 2.Intensity check in manufacture procedure. 3.Eliminate leakage oil of oil circuit system. |
| 4 | Useful Life Of Hydraulic Valve Is Not Reach Criterion. | 1.Wear of details are very graveness. 2.Oiliness is not eligible or not pass third class filtration. 3.The system have a much of dirty and impurity. | 1.Replacing wear details 2.Testing hydraulic oil before using. 3.Stricness using system of hydraulic. |
| 5 | Control Of Hydraulic Valve Is Ineffective | 1.Overpressure using 2.Regulation screw thread wear severity. | 1.Forbid overpressure using. 2.Replacing the regulation screw thread. |
| 6 | Valve Body Leakage | Valve body appeared slit. | Replacing the valve body |
| 7 | Hydraulic Valve Motion Is Powerless, Tardive And Lag | 1.Oil circuit system is leakage oil, valve have outer leakage. 2.Oil circuit system is dirty, 3.Hydraulic oil contained impurity. 4.Within leakage rate is exceed, component is wear. | 1.Check the system, eliminate leakage 2.Strictness implement “third class filtrate”. 3.Replacing and refit the component. 4.Repair seal or parts. |
| 8 | Anti Commutation Of Spool Valves | 1. The spool valves choked to death 2. The valve bodies to transform 3.have to break to the medium spring in the center potentially 4. The pressure not enough 5.electromagnet coils of the operate pressures burn bad or the electromagnet thrust shortage 6.The electricity circuits break down 7.Liquids to control the commutation valve control oil road without the oil or is stop | 1.Tear open to clean the booty, go to the hair to stab 2.Regulate the valve body to set the bolt to make pressure even, or fix the strict valve hole 3.Replace the spring 4.The operation pressures must be big in the 0.35 Mpa 5.Teat, mend, replace 6.Cancellations break down 7.Look over the reason and combine cancellation |
| 9 | The Direction Valve Of The Solenoids Have The Noise When Act | 1.The spool valves block or friction over 2.The electromagnet can’t press exactly 3.The solenoid core contact surface gravamen or contact bad | 1.Fix strict or deploy slide valve 2.Correct the electromagnet high 3.Cancellation dirty oil, correction the solenoid core |
| 10 | Oil Anti Countercurrent | 1.Control pressure over low 2.Control the oil pipe pass connectors leak the serious 3. The seat part of one-way valves of oil was blocked | 1. Control the pressure to make it attain the request value 2.Tight connector, cancellation leak oil 3.Cleaning |
| 11 | Against Way of Free flow Seal, Have The Leak The Oil | 1.One-way valves seat or ball is blocked on the full operation place 2. One-way valve’s drill surfaces and the surface contact asymmetry of valve seat drill | 1. Repairs or cleaning the sealing parts to see if it is available to work 2. Check to fix or replace parts |
