Hydraulic torque pump is the power unit of a hydraulic wrench. Hydraulic tensioner pump is the power unit of a bolt tensioner. It is an energy conversion device that converts mechanical energy into fluid pressure energy, and is an energy device that provides pressure oil to the hydraulic transmission system. It is driven by the engine (internal combustion engine) or electric motor, sucks in the oil from the hydraulic oil tank, forms the pressure oil and discharges it, and sends it to the actuator. Hydraulic pump is the hydraulic power pack of hydraulic torque wrench or bolt tensioner.

How Does A Hydraulic Power Pack Working?

The working principle of a hydraulic pump is that movement changes the pump cavity, thereby compressing the fluid and making the fluid have pressure energy. The necessary condition is that the pump cavity has a sealed volume change.

Hydraulic power pack machine is a kind of hydraulic component that provides pressurized liquid for hydraulic  power pack system. It is a kind of pump.

It converts the mechanical energy of power machines (such as electric motors and internal combustion engines) into pressure energy of liquids.

Its cam is driven by a motor to rotate. When the cam pushes the plunger upwards, the seal volume formed by the plunger and the cylinder body is reduced, and the oil is squeezed out of the seal volume and discharged to the place where it is needed through the one-way valve.

When the cam rotates to the lower part of the curve, the spring forces the plunger down to form a certain degree of vacuum, and the oil in the oil tank enters the sealed volume under the action of atmospheric pressure.

The cam causes the plunger to rise and fall continuously, the sealing volume periodically decreases and increases, and the hydraulic power pump continuously sucks and discharges oil.

Hydraulic Torque/Tensioner Pump Classification And Difference

TorcStark’s torque/tensioner pumps are mainly divided into the following series.

According to the purpose, it can be divided into hydraulic torque wrench pump and hydraulic bolt tensioning pump.
Torque pumps are mainly used for hydraulic torque wrenches. Generally, its maximum working pressure is 70MPa (10000psi).
Tensioning pumps are mainly used for hydraulic bolt tensioners. Generally, its maximum working pressure is 150MPa (21750psi).

According to the power source, it can be divided into electric hydrolic pump, gas powered hydraulic pump, hydraulic hand pump, gasoline engine driven hydraulic pump, pneumatic hydraulic pumps, hydraulic pump air driven.

1. The hydraulic electric pump is mainly driven by a motor. It has a fast speed under light load and a low speed under heavy load and the bolt tightening is more accurate. Equipped with a brushless high-power motor, which is easy to maintain and has a longer life. With a starting capacitor, it can be started with a load, and the operation is simple.

2. The air driven hydraulic pump uses compressed air as the power source, which has the characteristics of explosion-proof, safety, no heat, and long working hours. The high-performance pneumatic reversing valve makes it safe and reliable, with stable performance, and is suitable for dangerous working conditions such as coal mines.

3. The manual hydraulic pump is powered by human workmanship. The aluminum-titanium alloy pump body is light in weight, high in strength, anti-corrosion and anti-vibration.

4. The petrol engine driven hydraulic pump is driven by a petrol internal combustion engine. It is suitable for situations where there is no power supply and compressed air on site and it uses a high-power internal combustion engine, which has strong power and is easy to portable.

How To Correctly Use Hydraulic Power Pack Hydraulic Pumps For Beginners?

Here are a few simple steps:


1 Evaluate the bolt diameter, nut size, bolt grade, washer thickness, washer diameter, free bolt protrusion length, and bolt load requirements. Then you can check the technical specifications of the hydraulic torque pump to ensure that it provides the proper torque to achieve the required preload rate.

2 Use high-pressure tubing to connect the hydralic pump unit and hydraulic torque wrench/bolt tensioner.

3 Put the hydraulic torque wrench or bolt tensioner on the nut to be pre-tightened.

4 Control the high pressure hydraulic pump, input high-pressure oil to the hydraulic tensioner/wrench cylinder, the piston starts to work, and the hydraulic tensioner/wrench enters the working state. At this time, pay attention to the working pressure of the hydraulic torquing machine and the hydraulic tensioner/wrench. The working status must be controlled within the set range.

5 When the nut is fully tightened and the pump pressure reaches the preset pressure, press the retract button and the piston rod will retract. At this time, the nut pre-tightening is complete.


After the work is completed, first release the pressure of the high pressure hydraulic pump, and then disassemble. There are two disassembly methods, which can be selected according to the working environment:

1) Use the toggle handle to move the extension head, and firstly drain the hydraulic oil in the oil cylinder to the storage oil of the ultra-high pressure oil pump, reset the piston, and then disconnect the quick connector connected with the high-pressure oil pipe, and remove the hydraulic tensioner/wrench from the bolt, ending the whole process.

2) Disconnect the quick connector connected to the high-pressure oil pipe, first unscrew the hydraulic tensioner/wrench out of the bolt, loosen the screw on the end of the piston with an Allen wrench, and then clamp the bolt tensioner or hydraulic torque wrench flatly in the vise In the middle, slowly move the screw rod to drain the hydraulic oil stored in the cylinder until the pistons are all reset.

Hydraulic Power Units Hydraulic Pump Precautions

1 The oil pump uses specific oil.

2 The oil storage capacity must be within the range above the oil window.

3 Every time when refueling and changing the oil, it must be filtered with an oil filter screen of 80 mesh or more, and the oil tank must be cleaned when changing. The oil change period is six months.

4 The working oil temperature is 10 degrees Celsius to 50 degrees Celsius.

5 Before starting the hydraulic pump power unit, open the bleed nut and set the switch to the unloading position.

6 If the motor temperature is too high during use, stop using it and wait for it to cool down.

7 The hydraulic pump unit has been adjusted before leaving the factory, and it must not be adjusted at will. When re-adjustment is required, a pressure gauge must be used.

8 Before leaving the factory, the high-pressure hose has passed the 105MPA test. However, since the hose is prone to ageing, the user needs to check it frequently, usually every six months, or every three months if it is used frequently. Test it at 87.5MPA during inspection. If there is damage, bulge, or leakage, it cannot be used any more

9 Bearings are generally cleaned once every six months, and grease needs to be added during assembly.

Why Use A Hydraulic Pump?

Hydraulic power pack is the power source of hydraulic torque wrench and bolt tensioner, which can achieve maximum work efficiency and ensure construction safety.

The fuel tank and pump body of aluminum-titanium alloy are small in mass, easy to carry, simple in structure, and can obtain greater working pressure.

φ100 high-precision pressure gauge ensures high torque accuracy of the wrench.

The output pressure can be adjusted freely within the range of 40-700bar.

Equipped with a radiator, it can work continuously for 24 hours without interruption.

Various types of engines can be equipped according to customer requirements.

Application Of Hydralic Unit Hydraulic Pump

Our hydraulic torque pump can be used for any type of hydraulic wrench, such as square drive hydraulic wrenchlow profile hydraulic wrench. It can be selected according to different hydraulic tools.

Generally speaking, hydraulic power pack hydraulic pump is suitable for electric power (nuclear power, wind power, hydropower, thermal power), shipbuilding, metallurgy, transportation, cement, construction, aviation, petrochemical, construction, mining and other industries.

It is a very important tool for installing and removing large bolts.

For example, the installation of wind turbine towers and blades, the fastening of bolts, the bolt fastening of subway rails, and the bolt fastening of large-scale mine cars in mines all require pressure hydraulic pump. anti explosion hydraulic pumps can be used in coal mine environments.

Where To Buy Hydraulic Power Unit?

Know the working conditions of your project, such as whether there is power supply and compressed air, and whether it is in an extremely confined environment.

Know whether you are a dedicated user or a temporary user of portable hydraulic pumps, whether you need a multifunctional hydrualic power unit or a universal type, the maximum torque output required, whether the material of the torque pump is steel or aluminum titanium alloy, and so on.

When you choose a hydraulic pack, we will tell you to choose the matching hydraulic torque wrench power pack. According to the actual working conditions, the choice is one for one, one for two or one for four hydraulic torque wrench pumps (that means how many hydraulic wrench can be driven by one hydraulic torque pump).

TorcStark’s hydraulic pumps is made of aluminum-titanium alloy, which is light in weight and high in strength. We have a complete system supporting supply capacity, complete types and specifications, and has passed the quality certification of CE, ISO9001 and other institutions.

TorcStark is a professional hydraulic power pack hydraulic pump manufacturer and supplier. So, TorcStark double acting hydraulic pumps is a best choice. You can tell our product experts about your needs or your business via email, and we will provide you with the best product portfolio plan, or customize a product portfolio suitable for your business.

If you are looking for a hydraulic pump with good quality and low price, please feel free to contact us by email(torcstark@gmail.com) get hydraulic pumps price list.