Reasons for the leakage of the hydraulic solenoid operated directional valves

Adjustable hydraulic pressure relief valves more or less have the problem of internal leakage, this is related to the structure and working principle of the solenoid operated directional valves, a certain range of internal leakage is normal, can not be completely avoided. The working principle of the pressure operated relief valve is that electromagnetic power push rod to make the relative movement of the spool after the electric drive, so as to open or close the corresponding oil hole. In order to ensure the smooth movement of the valve core in the valve body, need to maintain a certain gap between the two, otherwise the adjustable hydraulic pressure relief valve and the valve body will keep in close contact and  not be able to move under the influence of friction.

The gap size of the adjustable hydraulic pressure relief valve body and the valve core is known as the matching precision. It need to be strictly controlled in order to ensure the stability of the 50 psi pressure relief valve. The internal leakage of the hydraulic system directly affects the working efficiency of the hydraulic system, and can easily lead to malfunction of the system.

But need to point out that the matching precision of the pressure operated relief valve is not simply the pursuit of precision, but should select the most appropriate solution based on the requirements of the work conditions and cost.As we all know, the hydraulic system in the hydraulic oil is very easy to mix with small impurities and it is difficult to completely eliminate. It is usually used to filter the impurities in the fuel tank with a single filter. This method is relatively simple, but the accuracy of the low cost filter is limited, can not effectively filter small impurities. If the matching precision of the hydraulic solenoid valve above the filter precision, valve core is easy to be blocked by the impurities not filtered , resulting in the solenoid valve failure. For high precision solenoid operated directional valve, it is generally recommended to adopt high precision filtration equipment, such as cotton core, which will increase the cost of the whole system. Therefore, the requirements for the electromagnetic solenoid operated directional valves leakage should be based on the actual work situation.

Some low price 50 psi pressure relief valves can increase the internal leakage after a certain period of time, may be due to the valve body using of low hardness material, the gradual wear and tear in the work lead to poor accuracy.

If pressure operated relief valves connection surface oil leakage, generally should check the installation of adjustable hydraulic pressure relief valve and the bottom plate is flat or not, the torque and the material of connecting bolts should be consistent. The problem that is often overlooked is that the hardness of the O type ring is mounted. The lower hardness of the sealing ring should not be used for the sealing of the high-pressure system, can be replaced if necessary.

Fault solution for leakage of electromagnetic 3 position 4 way directional control valve

Modular controls solenoid valve due to the material, processing accuracy, the use of wear and other reasons, there may be an abnormal increase in internal and external leakage, resulting in a decrease in pressure, or through the flow problem and other issues.

The leakage of electromagnetic modular controls solenoid valve leakage is increased, the most common problem for the O type sealing ring. Should check whether the O ring is installed in place, if there is a squeeze, damage and other issues, it is best to replace the sealing ring.

Also need to check the size of the sealing ring, and whether it is consistent with the size of the sealing surface, O type of ring is too large or too small will affect the sealing effect.

Secondly, O type ring material hardness in high pressure situation will also affect the stability of the seal, the lower hardness of the O ring is not suitable for solenoid operated relief valve seal, should choose high hardness O type ring to get better sealing effect.

The internal leakage of the electromagnetic 3 position 4 way directional control valve is increased, which causes the system pressure to reduce, the flow loss, and the work efficiency of the hydraulic system. Common cause of this failure is solenoid operated pressure relief valve body hole and spool wear in the long-term movement of the process of friction,lead to excessive solenoid operated relief valve clearance, causing leakage. Can repair the outer diameter of the spool, or replace the valve core.The material hardness of valve core and valve body directly determines its service life.

Main advantages of electromagnetic directional control valve

1.Security

Internal and external leakage is a risk factor for safety. Other automatic directional control YUKEN DSHG 06 valve will generally stem, control directional valve to rotate or move by electric, pneumatic or hydraulic actuator. This is to solve the stem seal leakage problem of long-term operation of the rexroth directional valve.

A.Internal leakage. Electric directional control dshg 06 yuken valve torque is not easy to control, prone to internal leakage, and even pull off the stem head; the electromagnetic directional valve leakage within the structure type is easy to control, until reduced to zero.

B.External leakage. Solenoid directional dshg 06 yuken valve is completed by the electromagnetic force acting on the magnetic core in the magnetic seal, there is no dynamic seal, so it is easy to plug the leakage.

In summary, the use of special safety valve, particularly suitable for corrosive, toxic or high temperature media.

2.Cost performance

A.Solenoid directional control YUKEN DSHG 06 valve itself is simple and low price, and is easy to install and maintain than other types of directional control valves .

B.The composition of the automatic control system is much simpler, and the price is much lower.

C.As the solenoid directional dshg 06 yuken valve is a switch signal control, and industrial computer connection is very convenient.

3.Energy saving

A.Solenoid directional control YUKEN DSHG 06 valve response time can be as short as a few milliseconds, even if the pilot solenoid directional valve can be controlled within a few tens of milliseconds.As a result of the loop, it is more sensitive than the other control valve.The power consumption of properly designed solenoid directional valve coil is very low.

B.Also can be done only to trigger the action, automatically maintain valve position, usually do not consume power. Solenoid directional control dshg 06 yuken valve small size, space saving, but also light and beautiful.

The purchase method of electromagnetic reversing control valve

1.WEHD rexroth hydraulic solenoid valve used to control the electric hydraulic control valve spool movement with electromagnet, and the structure and type of electric hydraulic control valve can be a variety of, such as two position two way, two position three way, two position four way, three position four way and three position five way types. In general, two position control valve with an electromagnet, three position valve with two electromagnets.

2.The electromagnet which control electric hydraulic control valve is divided into AC and DC two kinds, AC solenoid voltage is generally 220 volts. Its characteristic is the big start the power, short commutation time and low price. But when the spool jammed suction or not enough to absorb the core, the electromagnet is easy to burn out because the current is too large , therefore, the work reliability is poor, impact when action, life is lower. DC solenoid voltage is generally 24 volts. The utility model has the advantages of reliable work, will not burn because of spool jammed, long life and small size, But the starting power is less than the AC solenoid, and need rectifier equipment in the absence of DC power.

3.According to the structure of the electromagnet can be divided into dry type and wet type, each type has AC, DC and the entire form. And there are many kinds of power supply voltage, so there are a lot of differences in the structure. Because the internal wet electromagnet is connected with the back oil chamber, can reduce the wear when the armature moving in the oil,and improve thermal performance and the service life. AC electromagnet has the advantages of short operation time, simple electrical control line, no special contact protection. DC electromagnet is characterized by soft switching characteristics, high frequency operation, not sensitive to the overload or low voltage response, stable and reliable. In recent years, the domestic and international is increasingly wide use of wet electromagnet. The WEHD rexroth hydraulic solenoid valve push rod without sealing, eliminates the friction of O ring. It directly use the engineering plastic seal outside electromagnetic coil, do not have to do the metal shell, this not only ensures the insulation, but also conducive to heat, so the work is reliable, the impact is small, long life.

Several types of direction control valves

1.Manual reversing yuken dsg-01 direction control valves:manual valve is use of the manual lever to change the spool position to achieve the reverse.

2.Motorized reversing direction control dsg-01-3c2 valves: also known as stroke valve, it is mainly used to control the movement of hydraulic machinery parts, which is the use of a block on the working table or cam to force thespool to move, so as to control the flow direction of oil. Motor reversing yuken dsg-01 valve is usually two position, there are two way, three way, four way and five way of two position directional control dsg-01-3c60 valve.Two position two way and two position three way directional control valve divided into common open and common closed.

3.Solenoid direction control dsg-01-3c2 valve: using the power of the electromagnet(on/off) to directly promote the valve core to control the oil port connected state.

4.Hydraulic reversing directional control dsg-01-2b2 valve

5.Electro hydraulic reversing valve: by the combination of electromagnetic valve and hydraulic directional control dsg-01-3c60 valve. Solenoid direction control valves play a leading role, it can change the direction of the flow, so as to change the position of the hydraulic directional control valve. Because of the hydraulic pressure of the hydraulic directional control valve can be very large, so the main valve can be great, allowing a greater flow through. Such a small electromagnet can be used to control large liquid flow.

6.Proportional solenoid direction control dsg-01-2b2 valve: the proportional direction control valves control the movement of the valve core with the electromagnetic force generated by the electromagnetic coil of the valve core, control the direction of the valve spool displacement by controlling the coil current, so that it can control the direction and flow of oil flow.

Matching problem of solenoid hydraulic valves power supply

Some time ago, a client of mine encountered a problem that hydraulic YUKEN DSG-03 solenoid valve can not be opened.24V power supply to 9 solenoid valves by switching power supply,use collinear supply power to 9 solenoid hydraulic valves at the same time,and control signal to control the action of an hydraulic dsg solenoid valve.But why do often solenoid hydraulic valves can not move? What is the reason?

Through the specific communication, we learned that customer use the 1.5 party line length of 230 meters, so it is not difficult to understand why the solenoid hydraulic valve does not move.Because the power supply voltage selection of 24V, we need to consider the loss, if the cable is too thin and too much, loss will be too large. When the power supply to the YUKEN DSG-03 solenoid valve coil, the voltage is only 16V, has been lower than the normal open voltage of 20V, leading to the solenoid valve coil can not act. There are 9 solenoid hydraulic valve at the same time, so that the terminal voltage and power must be guaranteed to the solenoid hydraulic valves.