What Compressor Is Needed For A Pneumatic Wrench
How to choose a compressor for pneumatic tools?
The article is devoted to compressors for pneumatic tools. The main criteria for choosing this equipment are considered, and its manufacturers are also named.
Dimensions and design features
In addition to technical and operational indicators, it is important to take into account characteristics such as mobility and size. For example, if you intend to work with a spray gun to paint a fence, then you should turn to lightweight and ergonomic devices. Even if they provide a minimum level of performance, it is more likely to be sufficient for simple operations. Such models, in particular, include a coaxial compressor for pneumatic tools. The choice in this direction can be guided by oil-free equipment, which does not have a receiver at all, but benefits from compactness. If you need a powerful and efficient compressor with a massive casing, then it is recommended to purchase models equipped with comfortable handles and wheels.
How to choose a compressor for pneumatic tools?
The compressor is a must for most air tool models. Such equipment is used both in private households and in specialized workshops. There is also a separate category of industrial equipment, whose representatives also require the connection of compressors. The variety of pneumatic units makes it difficult to select additional components, however, provided the correct equipment is used, the user can count on a quality result in the process. The question of how to choose a compressor for a pneumatic tool, of course, primarily involves a mention of functionality, reliability and durability. But even compliance with these characteristics does not always provide the expected effect from using the tool.
Basic selection parameters
An experienced technician evaluates compressors according to three main characteristics, including pressure level, capacity and receiver volume. For the first criterion, the starting point is 6 bar. This is the minimum pressure that a compressor has for a pneumatic tool designed to perform simple household operations. Models with a pressure level of 10-15 bar are also common. This equipment is capable of working with more demanding units, including those from the industrial sector.
Compressor capacity is expressed in liters of working mixture sprayed per minute. So, for small-scale painting activities, 10-50 l / min is enough. But this range can be extended to 500 l / min when it comes to the use of equipment in the workshop. The volume with which a compressor for pneumatic tools for household use works is on average 7-10 liters. Of course, there are also more spacious receivers, but they are mostly used in highly specialized areas.
Additional equipment. What to consider?
Buying just one compressor does not mean that the connection to the instrument will be properly configured, and the work will be done well. The technical organization of the process often involves the use of special hoses, adapters and clamps. As practice shows, even a lightweight pneumatic tool, when connected to a compressor, requires the use of clamps with suitable dimensions. Personal protective equipment should not be ignored either. If the compressor for the pneumatic tool will spray abrasive materials, then you must take care of ear protectors, gloves and goggles. To work with paint and varnish compositions, it is also recommended to purchase overalls that will provide protection against chemically hazardous substances.
What kind of compressor do you prefer?
Segmentation of compressor types according to design also helps to make the right choice for inexperienced users. Models that are marketed as automobiles are suitable for most household needs. From painting surfaces to inflating rubber mattresses. A piston unit, which is used by workers in workshops and ordinary car owners, can also be a win-win solution. If the question is about which compressor is needed for a professional pneumatic tool, then you should pay attention to screw and belt models. Such devices usually have high power ratings and pressure levels.
Compressor manufacturers
Almost every manufacturer of construction or industrial equipment includes compressors in the line for different purposes. If we talk about domestic companies working in this direction, then Caliber and Elitech come to the fore. The products of these brands may not always be able to compete with the best foreign models, but for the price it is the most profitable acquisition. However, the question of how to choose a compressor for pneumatic tools with a high level of quality should be solved with the help of foreign products. The assortment in this segment is quite wide, but the brands Fubag, Metabo, Senco and others are the most trusted by experts.
The device and principle of operation of the pneumatic wrench
In the figure below, you can see in detail the device of the pneumatic wrench. The unit consists of the following elements housed in a robust metal case.
- High performance air motor.
- Impact mechanism.
- Alloy steel chuck (stop).
- Torque regulator, and reverse.
- Start button.
- Fitting for connecting a hose from the compressor.
- Air valve.
Inside the unit, 2 main power units can be distinguished, each of which is designed to operate in different modes. The first unit is an air motor that transmits rotary motion to the tool head. The second block is the node that creates shock loads. The pneumatic actuator rotates due to the passage of compressed air through it, supplied by means of a high-pressure hose from the compressor.
There are 2 channels in the body of the device. For each of them, air is directed in different directions relative to the turbine. In the first case, the air pushes the turbine in the clockwise direction, that is, for twisting, and in the second, against the clockwise arrow, in unscrewing the fasteners. Air flows are distributed by a special switch.
The principle of operation of a pneumatic wrench is as follows.
- After pressing the start button, the valve opens, and the air flow from the hose connected to the body of the apparatus begins to move through the turbine, rotating it.
- From the turbine, the rotary motion is transmitted to the impact mechanism, which in its principle of action resembles a clutch. The mechanism includes 2 cams of complex configuration. The impact force is generated by the cams when there is not enough torque when the fastener is released.
- Further, the rotational movement is transmitted to the stop (chuck), on which the nozzle is put on under a certain nut size. As a result, the fasteners are twisted or unscrewed. Some air wrenches do not use the impact mechanism when tightening, the process takes place in a shockless mode.
- If the nut is stuck, then it will take more effort to unscrew it, and at this moment the rotation of the stop stops.
- The hammers begin to tilt back while turning.
- At the next stage, the cams pass the engagement with the stop and, continuing to move, gain momentum.
- Continuing to turn, the cams again engage with the stop and strike it (in the direction of travel).
- Shock impulses continue until the fastener “breaks” from its place.
Thus, with the help of a pneumatic impact tool, the process of loosening tight bolts and nuts is quick and easy.
Lubrication rules
If for some reason you are not able to install the lubricator on your unit, then you can get out of the situation in the following way.
- Immediately before starting the wrench, it is necessary to unscrew the hose from it and drip 3 to 5 drops of grease into the tool fitting.
- Next, you should return the hose to its original place and turn on the unit for a short time (thirty seconds will be enough). Thanks to this operation, the oil will be evenly distributed over all the moving parts of the device.
Although this method helps to extend the life of the wrench, it is very inconvenient. We have to interrupt work and spend time cleaning the tool from contamination in the area of the fitting, preparing the lubricant. Also, during the procedure, you should carefully monitor that dust does not get into the unit. It is for these reasons that it is recommended to install a lubricator in the system, which will always supply lubricant to the tool in a timely manner.
The choice of oil for the wrench
The lubrication of this pneumatic tool should be taken very seriously. If the unit can work without purified air for some time, then without lubrication it will fail very quickly. Oil flowing to the moving parts of the machine reduces friction between them, and also removes wear products in the form of fine dust. This dust is able to fill the gaps between the blades and the rotor, which slows down their movement. As a result, the power of the tool is significantly reduced. The problem is solved by installing a lubricator in the system. The below shows its linear type.
But the installation of an “oiler” will help to extend the life of the nutrunner only if it is filled with a special grease intended only for pneumatic tools with the required viscosity.
Try to get the wrench oil recommended by the tool manufacturer. In extreme cases, only synthetic oil should be used, which has good anti-wear and anti-corrosion properties and does not contain silicone.
Special grease can also be purchased from pneumatic tool companies.
Hose selection
You should be aware that the hose that comes with the compressor, especially the Chinese one, is not suitable for the effective operation of the wrench. Most often, these hoses have an internal cross-section of about 6 mm. This hose capacity will not be enough to supply the required amount of air to the pneumatic tool. They, perhaps, can blow off dust, apply for a spray gun, but no more. Even pumping tires with it takes a lot of time.
Choosing a compressor for a pneumatic wrench
Many motorists, buying a pneumatic wrench, are wondering what kind of compressor is needed for this unit. First of all, you should pay attention to its performance according to the passport. There is one caveat here: some companies that produce compressors, in order to increase sales, indicate the performance not at the outlet, but at the inlet. For example, in the documentation for the unit, its productivity is 210 liters per minute. This means that this indicator should be interpreted as the speed of air injection by the compressor into itself, that is, into the receiver. At the output, the productivity can drop by about 30-40%. And it turns out that the unit actually produces only 146-127 l / min.
Based on the foregoing, it can be understood that if the compressor has a capacity of 210 l / min, then you need to choose a wrench with significantly lower air flow rates. For example, if the operating speed of the air flow for the tool is 200 l / min, and the compressor, according to the documentation, is 210 l / min (in reality. 146-127 l / min), then you will not be able to unscrew or tighten anything with such a tool.
In addition, the volume of the receiver also plays an important role. In household appliances, a cylinder can have a volume of only 24-50 liters. Under these conditions, the impact wrench will not work properly. Even with a receiver volume of 50 liters, after a few seconds of operation of the tool, the pressure in it decreases significantly, and to continue work you have to wait until it recovers. Therefore, the compressor receiver must have a volume of more than 50 liters, and the unit itself must create a pressure in it of at least 6.2 kg / cm². Otherwise, the device will not be able to develop the required power.
The result of the above is this: if the tool is designed for an operating air speed of 119 l / min, and the compressor for the wrench produces 135 l / min in reality, then with its help you can easily unscrew and tighten the fasteners on the wheels. But do not forget that the tool must have a torque of at least 550 Nm.
Features of the operation of a pneumatic wrench
Any craftsman knows that the most laborious process when installing structures or repairing mechanisms is loosening and tightening threaded connections. But if pneumatic wrenches are used for these purposes, then such work turns into an ordinary formality. This handy tool has many advantages, but you should learn more about the nuances of its operation.
The choice of oil for the wrench
The lubrication of this pneumatic tool should be taken very seriously. If the unit can work without purified air for some time, then without lubrication it will fail very quickly. Oil flowing to the moving parts of the machine reduces friction between them, and also removes wear products in the form of fine dust. This dust is able to fill the gaps between the blades and the rotor, which slows down their movement. As a result, the power of the tool is significantly reduced. The problem is solved by installing a lubricator in the system. The below shows its linear type.
But the installation of an “oiler” will help to extend the life of the nutrunner only if it is filled with a special grease intended only for pneumatic tools with the required viscosity.
Try to get the wrench oil recommended by the tool manufacturer. In extreme cases, only synthetic oil should be used, which has good anti-wear and anti-corrosion properties and does not contain silicone.
Special grease can also be purchased from pneumatic tool companies.
Why does a compressor need a filter
The air leaving the compressor must be clean, that is, free of various impurities that can damage the wrench. Not everyone knows that condensation forms in the interior of the receiver during air compression. Also, oil can get into the receiver along with the forced air if the mechanical part of the unit is severely worn out. Oil, mixing with condensate (moisture), takes the form of an emulsion and enters the instrument through a hose connected to it. This emulsion can corrode all mechanical parts of the unit. For this reason, wrenches filled with water and rust, with failed components, often come to service workshops.
In order not to bring the tool to such a deplorable state, it is customary to install a filter-moisture separator on the compressor. Inside it is a filter mesh made of bronze using a special technology.
The air passing through the filter gives off moisture and loses all impurities that enter the sump. Typically, the body of the moisture trap is made of a transparent material to track the amount of contamination accumulated during operation.
Lubrication rules
If for some reason you are not able to install the lubricator on your unit, then you can get out of the situation in the following way.
- Immediately before starting the wrench, it is necessary to unscrew the hose from it and drip 3 to 5 drops of grease into the tool fitting.
- Next, you should return the hose to its original place and turn on the unit for a short time (thirty seconds will be enough). Thanks to this operation, the oil will be evenly distributed over all the moving parts of the device.
Although this method helps to extend the life of the wrench, it is very inconvenient. We have to interrupt work and spend time cleaning the tool from contamination in the area of the fitting, preparing the lubricant. Also, during the procedure, you should carefully monitor that dust does not get into the unit. It is for these reasons that it is recommended to install a lubricator in the system, which will always supply lubricant to the tool in a timely manner.
Choosing a compressor for a pneumatic wrench
Many motorists, buying a pneumatic wrench, are wondering what kind of compressor is needed for this unit. First of all, you should pay attention to its performance according to the passport. There is one caveat here: some companies that produce compressors, in order to increase sales, indicate the performance not at the outlet, but at the inlet. For example, in the documentation for the unit, its productivity is 210 liters per minute. This means that this indicator should be interpreted as the speed of air injection by the compressor into itself, that is, into the receiver. At the output, the productivity can drop by about 30-40%. And it turns out that the unit actually produces only 146-127 l / min.
Based on the foregoing, it can be understood that if the compressor indicates a capacity of 210 l / min, then you need to choose a wrench with significantly lower air flow rates. For example, if the operating speed of the air flow for the tool is 200 l / min, and the compressor, according to the documentation, is 210 l / min (in reality. 146-127 l / min), then you will not be able to unscrew or tighten anything with such a tool.
In addition, the volume of the receiver also plays an important role. In household appliances, a cylinder can have a volume of only 24-50 liters. Under these conditions, the impact wrench will not work properly. Even with a receiver volume of 50 liters, after a few seconds of operation of the tool, the pressure in it decreases significantly, and to continue work you have to wait until it recovers. Therefore, the compressor receiver must have a volume of more than 50 liters, and the unit itself must create a pressure in it of at least 6.2 kg / cm². Otherwise, the device will not be able to develop the required power.
The result of the above is this: if the tool is designed for an operating air speed of 119 l / min, and the compressor for the wrench produces 135 l / min in reality, then with its help you can easily unscrew and tighten the fasteners on the wheels. But do not forget that the tool must have a torque of at least 550 Nm.
Hose selection
You should be aware that the hose that comes with the compressor, especially the Chinese one, is not suitable for the effective operation of the wrench. Most often, these hoses have an internal cross-section of about 6 mm. This hose capacity will not be enough to supply the required amount of air to the pneumatic tool. They, perhaps, can blow off dust, apply for a spray gun, but no more. Even pumping tires with it takes a lot of time.
Features of the operation of a pneumatic wrench
Any craftsman knows that the most laborious process when installing structures or repairing mechanisms is loosening and tightening threaded connections. But if pneumatic wrenches are used for these purposes, then such work turns into an ordinary formality. This handy tool has many advantages, but you should learn more about the nuances of its operation.