(Last Updated On: March 23, 2023)

If you often use hydraulic wrenches or hydraulic tensioners, you must be familiar with hydraulic pumps. The hydraulic pump provides power for the hydraulic wrench and bolt tensioner to perform operations such as bolt pre-tightening and tightening. But you may encounter some problems that need to be solved in the process of using the hydraulic pump. Now, TorcStark lists some common hydraulic pump failures and solutions for reference.

Hydraulic wrench pump safety valve leakage and solution

1. Reasons for the leakage of the safety valve of the hydraulic wrench pump:
The reasons for the leakage of the safety valve of the general hydraulic wrench pump may be caused by damage to the sealing surface, improper installation, high temperature, opening pressure too close to the working pressure of the equipment, or dirt entrained on the sealing surface.

2. The leakage of the safety valve of the hydraulic wrench pump can be solved by referring to the following methods:
(1) According to the degree of damage, it is repaired by grinding or grinding after turning. After repair, the flatness of the sealing surface should be guaranteed, and the smoothness should not be less than 10.
(2) Reassemble and remove the additional load of the pipeline.
(3) When the selection is improper, a safety valve suitable for a high-temperature medium should be re-selected according to the operating temperature, such as a safety valve with a radiator or other special structure safety valves. For leakage caused by a high-temperature environment, appropriate heat insulation measures should be taken.
(4) Re-set the pressure according to the permissible range of the working pressure of the spring. If it exceeds the working pressure range, replace the spring with a working pressure level that matches it.
(5) Use a lift wrench or other methods to open the valve several times to blow off the dirt. If it cannot be blown off, disassemble the valve to remove it.

What to do if the oil level of the hydraulic oil tank is too low

Add suitable hydraulic oil to the standard position, and there is a scale showing the level of hydraulic oil in the oil tank of the hydraulic pump. Just add enough hydraulic oil according to the user manual.

What to do if the hydraulic oil is not used according to the season

Generally speaking, 46# hydraulic oil (or 68#) does not need special replacement and can be used throughout the year. In special cases, consider using 32# when the temperature in the north is low in winter.

What to do if the hydraulic pump cannot be pressurized

Possible causes: 1. The release valve is defective; 2. The air supply is too low or the air hose is too thin; 3. The voltage is too low; 4. The instrument is defective; 5. The oil level is too low; 6. The oil filter is blocked.

Specific solutions:
1. Check, adjust or replace the release valve;
2. Make sure that the size of the air supply and hose is consistent with the regulations on the pump manual;
3. Make sure that the voltage, current and extension wire size are consistent with the requirements in the pump manual;
4. Replace the instrument;
5. Check and fill the oil tank of the pump; 6. Check, clean and replace the pump oil filter.

What should I do if the pressure display is unstable?

Possible cause: The meter is defective.
Specific solution: replace the instrument.

What to do if the hydraulic pump pressurizes slowly

Possible reasons:
1. The valve core sealing ring of the solenoid valve is worn;
2. Air enters the hydraulic oil.

Specific solutions:
1. Replace the valve core sealing ring;
2. Remove the air in the hydraulic oil.

Hydraulic pump cavitation phenomenon and its solution

1. Hydraulic pump cavitation
Cavitation is one of the common problems with hydraulic pumps. The internal pressure will gradually decrease with the increase of the volume of the working chamber, and the oil will be sucked into the pump working chamber when the pressure in the pump working chamber is lower than the inlet pressure of the pump. Compared with the air separation pressure, the minimum pressure of the pump working chamber is smaller than it. Therefore, the air dissolved in the oil will be separated, resulting in a large number of air bubbles in the liquid in the working chamber of the hydraulic pump, and the cavitation phenomenon of the hydraulic pump will result from this. In addition, when the pressure in the working chamber of the pump is greater than the saturated vapor pressure of the liquid, the oil will also vaporize, which will further aggravate the cavitation of the hydraulic pump.

2. Solution to hydraulic pump cavitation:
(1) Increase the diameter of the oil suction pipeline, reduce or avoid the bending of the oil suction pipeline, so as to reduce the oil suction speed and reduce the resistance loss of the pipeline.
(2) Choose an appropriate oil suction filter, and check and clean it frequently to avoid clogging.
(3) The suction height of the hydraulic pump should be as small as possible. Hydraulic pumps with poor self-priming performance should be supplied with oil by a low-pressure auxiliary pump.
(4) Avoid insufficient oil absorption caused by excessive hydraulic oil viscosity.
(5) Use the correct piping method.

Standard and frequency of hydraulic wrench pump oil change

Hydraulic wrench pump oil change standard

1. Dust enters the oil tank to make the oil dirty;
2. produce peculiar smell;
3. The oil is mixed with water, and the oil is emulsified;
4. Deterioration and discoloration occur,

Hydraulic wrench pump oil change requirements and frequency

1. The viscosity-temperature performance is good. It is required that within the working temperature range, the viscosity range should be small. Generally, the hydraulic oil temperature index is above 90;
2. Good anti-rust performance, requiring hydraulic oil to have good anti-rust performance;
3. The anti-oxidation performance is better, the oxidation speed is very fast, and the oil will oxidize, which will generate cement sedimentation residue and affect the normal operation of the system;
4. Good anti-emulsification performance and good anti-foam performance;
5. The lubricating performance is good, and it is required to form a high-strength oil film on the moving surface in order to form liquid lubrication and reduce wear;
7. The freezing point should be 10°C lower than the lowest ambient temperature

If the hydraulic wrench is used for the first time, it is recommended to replace the hydraulic oil once after 48 hours of continuous work. For example, wind power installation companies have a relatively high frequency of use, or if the working environment is poor, it is recommended to change it at least once a month. The working environment of general manufacturing enterprises is relatively clean, and if the frequency of use is not high, it should be replaced at least once every six months.

In the end

The above are the common problems and solutions about hydraulic wrench pump or hydraulic stretching pump. TorcStark has many years of experience in manufacturing hydraulic pumps. If you encounter any problems during use, please contact us. Our experienced engineers will provide you with professional technical support.