Compressor bleeds air. Possible Causes of Insufficient Performance of a Screw Compressor

Reducing the operating pressure is an undesirable process, especially if we are talking about expensive pneumatic equipment. This problem must be taken seriously, since the efficiency of the entire compressed air supply system will depend on its solution. This article describes the reasons why the compressor does not build up pressure, as well as the actions to be taken if such a situation occurs.

Operation and maintenance

First of all, it should be noted that even with timely maintenance, equipment, or some of its elements, wear out sooner or later.

Before starting the operation of the compressor, it is necessary to carefully read all the factory rules and recommendations, as well as regularly inspect the external structure. Any, even minor external damage can lead to premature failure of the equipment, as well as to the fact that the compressor stops pumping pressure.

It is highly desirable to entrust all technical operations to experienced professionals who use professional tools and diagnostic devices.

The main reasons why the air compressor does not gain pressure: ways to fix it.

Depressurization of connecting elements and nodes.
When subjected to vibration for a long time, seals, nuts and clamps may loosen, resulting in air leakage. First of all, the user needs to check the basic threaded connections and pipes. As well as attachment points measuring devices(pressure gauge), valves and other modules. When a problem is found, take wrench of the appropriate size and tightly tighten all nuts, couplings. In some cases, the gaskets may need to be replaced.
If after the above procedures the problem is not resolved, the user should arm himself with a soapy solution and coat all connections with it. After starting the compressor, bubbles will form at the place of depressurization. Special attention a condensate drain valve must be provided. As experience shows, most of these problems occur in this area.
Worn compression rings and valve plates.
Another answer to the question why the compressor is not gaining pressure.
To begin with, the master must check the suction by unscrewing the air filter, and the exhaust force at the outlet of the piston block.
During the operation of piston pneumatic stations, the main load falls on the sealing rings. Their replacement will not require large expenses, and the master will carry out the procedure quickly enough.
Breakage is also a common problem. check valve. This is usually accompanied by compressor overheating. It must be disassembled and checked for faults or foreign elements.
Reduced motor power.
Often work efficiency electric motor decreases due to internal pollution and soot. Sometimes this is due to the use of unsuitable technical fluids or poor quality oils. Also, users do not always regularly check the engine air filter, which clogs the piston group, rings and other elements of the mechanism. In this case, an increase in the consumption of lubricating fluids and clogging of the pneumatic flow with oil occurs. Over time, parts can begin to overheat and fail.
The electric motor must be inspected and serviced by an experienced technician. In some cases, it may be necessary to replace a large number of expensive parts.

During the operation of compressor equipment, situations arise when the compressor does not gain pressure. This usually occurs after a sufficiently long period of operation. The reasons for this situation may be different.

This problem is often discussed on the compressor forum.
Forum users give different answers to the question why the compressor is not gaining pressure. Most often, they advise starting by checking the pressure regulator settings. If the settings are not violated, proceed to the inspection of the compressor. The connection points of the nozzles at the inlet to the receiver and at the outlet of the cylinder are checked. Strong vibration can loosen the threaded fasteners, which causes pressure loss.

The threaded connection may be loose at the point where the pressure gauge or relief valve is attached. Relief valve overpressure during operation it can also lose tightness, but this problem is easily solved, just tighten the threaded connections tightly. Not always the weakening of the fastening can be determined visually. In this case, you can use a simple, but sufficient effective method. The soapy solution is applied with a brush to all joints. When the compressor is running, a bubble forms at the site of the air leak, which is easy to see. This is convenient because when the compressor is running, it is impossible to hear the air escaping due to the noise.

More difficult is the elimination of another common cause. Air leakage may occur in hard to reach place, under the cylinder or its head. Usually in such cases, they turn to repairmen, but if you have some experience, you can try to fix the problem yourself. To do this, remove the casing by unscrewing the bolts, lift the cylinder head and inspect the gasket. If the gasket is damaged, replace it and install the head in place, tightening the nuts alternately from different sides with a uniform force.

At reciprocating compressors common cause the fact that the unit cannot build up pressure is the operation of the compression rings, which are designed for certain period operation. Their untimely replacement leads to loss of power and pressure.

Another common cause of such a defect in reciprocating compressors is a loose fit, or valve failure. This reason can be assumed if the compressor is overheated, or the pressure build-up time is increased. In the most difficult cases The compressor does not build up pressure at all. Replacing the valve completely eliminates this problem.

During operation, the compressor motor also wears out, which leads to a loss of power, and, consequently, pressure.

A common cause of a malfunction is a clogged air filter at the inlet. Poor cleaning of the incoming air leads to the appearance of carbon deposits on the piston group and rings. All this causes an increase in oil consumption and its release, first into the receiver, and then into the network. As a result, the valve overheats and fails. Dust in the compressor causes a decrease in the service life of many components of the unit.

Regular preventive maintenance of compressors, timely replacement of end-of-life parts will help to avoid underpressure by the compressor and sudden emergencies.

There are situations when air compressor, peacefully rattling the engine in the corner of the garage, starts to falter, or even completely turns off. And at this moment, as luck would have it, there is a need for it. Do not be afraid, after studying the theoretical information, do-it-yourself compressor repair will not seem unattainable.

Purpose, main elements and principle of operation

The main purpose of air compressor units is to create a continuous uniform jet of compressed air. The flow of dense gas further actuate various pneumatic tools. These can be airbrushes, tire inflation guns, wrenches, cut-off machines, pneumatic chisels, nailers, and more. In the minimum configuration compressor unit equipped with a supercharger (motor that creates air flow) and a receiver (tank for storing compressed gas).

Compressors with an electric motor of a piston system have found the greatest application in auto repair shops. In the supercharger crankcase, a transmission rod moves along the axis back and forth, giving off an oscillatory moment to the reciprocating movement of the piston with sealing rings. The bypass valve system located in the cylinder head works in such a way that when the piston moves down, air is taken from the inlet pipe, and upwards it is returned to the outlet.

The gas flow is directed to the receiver, where it is compacted. Due to the design features, the supercharger produces an uneven jet of air. Which is not applicable for using the spray gun. A kind of capacitor (receiver) saves the situation, which smooths out pressure pulsations, giving out a uniform flow at the output.

A more complex design of the compressor unit involves hanging additional equipment designed to provide automatic operation, drying and moisturizing. And if in the case of a simple execution it is easy to localize a malfunction, then the complication of equipment execution makes it difficult to search. The following are the most common faults and solutions for the most common piston-type compressed gas supply systems.

Compressor unit defects

To facilitate the search for a problem, all defects can be classified according to the nature of the malfunction:

Compressor unit blower does not start
The compressor motor hums, but does not pump air or fills the receiver too slowly
At start-up, the thermal protector trips or the mains fuse blows.
When the blower is turned off, the pressure in the compressed air tank drops.
Thermal protector trips intermittently
The outlet air contains a large number of moisture
Engine vibrates a lot
Airflow is below normal

Consider all the causes of problems and how to fix them.

System blower does not start

If the engine does not start and does not hum, then the supply voltage is not applied to it. First of all, you should use indicator screwdriver check the presence of “zero” and “phase”, as well as the reliability of the connection of the plug to the socket. In case of poor contact, measures are taken for a tighter fit. If there is 220 V at the input of the circuit, the fuses of the compressor unit look.

Those that fail are replaced by passive protection devices of the same rating as the defective ones. In no case are hot-melt inserts designed for a larger electricity. If the fuse blows again, you should find out the cause of the failure - probably a short circuit at the input of the circuit.

The second reason why the unit does not start is that the pressure control switch in the receiver is faulty or the level settings have gone wrong. To check, the gas from the cylinder descends and the supercharger is started trially. If the engine is running, the relay is reset. Otherwise, the defective part is replaced.

Also, the engine will not start when the thermal overload protector trips. This device turns off the power circuit of the winding of the electrical appliance in case of overheating of the piston system, which is fraught with engine jamming. Let the blower cool down for at least 15 minutes. After this time, restart.

The engine hums, but does not work or produces low speeds

With an underestimated mains voltage, the electric motor does not master the scrolling of the axis, while it will buzz. With this malfunction, first of all, we check the voltage level in the network with a multimeter (it must be at least 220 V).

If the voltage is normal, then the pressure in the receiver is probably too high, and the piston does not master the pushing of air. In this case, the manufacturers recommend setting the “AUTO-OFF” automatic switch to the “OFF” position for 15 seconds, and then turning it to the “AUTO” position. If this does not help, then the pressure control switch in the receiver is faulty or the bypass (control) valve is clogged.

The last drawback can be tried to be eliminated by removing the cylinder head and cleaning the channels. Replace the faulty relay or send it to a specialized center for repair.

The start of the compressor is accompanied by a blown fuse or the operation of automatic thermal protection

This malfunction occurs if the installed fuse is lower than the recommended power rating or the supply network is overloaded. In the first case, we check the compliance of permissible currents, in the second, we disconnect part of the consumers from the electrical mains.

A more serious cause of the malfunction is the incorrect operation of the voltage relay or the breakdown of the bypass valve. We bypass the relay contacts according to the scheme, if the engine is running, then it is faulty executive device. In this case, it is better to contact the official technical support service center Or replace the relay yourself.

When the power supply is turned off, the air pressure in the receiver drops.

A drop in compressed air pressure indicates that there is a leak somewhere in the system. Risk areas are: air duct high pressure, piston head check valve, or reservoir bleed valve. We check the entire pipeline with a soapy solution for air leaks. We wrap the detected defects with sealing tape.

The outlet cock may leak if it is loose or defective. If it is closed all the way, and the soap solution on the spout is bubbling, then we change this part. When screwing in a new one, do not forget to wind the fum-tape onto the thread.

In the case of tightness of the air line and the outlet cock, we conclude that the compressor control valve is not working correctly. For execution further work be sure to bleed all the compressed air from the receiver! Next, we continue to repair the compressor with our own hands, disassembling the cylinder head.

If there is dirt or mechanical damage to the bypass valve, we clean it and try to fix the defects. If the problem persists, then replace the control valve.

Regular operation of automatic thermal protection

This defect is observed when the mains voltage is too low, the air supply is poor, or the air temperature in the room is high. We measure the mains voltage with a multimeter, it must be at least the lower limit of the range recommended by the manufacturer.

Poor air flow into the discharge system is due to a clogged inlet filter. The filter should be replaced or washed according to the maintenance installation. The piston engine is air-cooled and often overheats when in a poorly ventilated area. The problem is solved by moving the compressor unit to a room with good ventilation.

Exhaust gas jet contains a lot of moisture

This situation occurs under the following conditions:

Large accumulation of moisture in the receiver
Air intake filter dirty
Humidity in the compressor room is increased

Moisture in the output jet of compressed air is combated by the following methods:

Drain the excess liquid from the cylinder regularly
Clean or replace filter element
Transfer the compressor unit to a room with drier air or install additional filters-moisture separators

In general, piston engines are characterized by high vibration. But, if earlier a relatively quiet compressor unit starts to rumble, there is a high probability that the engine mounting screws have loosened or the material of the vibration cushions has become very worn. This malfunction is eliminated by pulling all the fasteners in a circle and replacing the polymer vibration isolators.

Compressor runs intermittently

Interruptions in the operation of the engine can be caused by incorrect operation of the pressure control switch or by too intensive selection of compressed air.

Excessive gas consumption occurs due to a mismatch between compressor performance and power consumption. Therefore, before buying a new pneumatic tool, carefully study its characteristics and air consumption per unit of time.

Consumers should not take more than 70% of the compressor power. If the power of the supercharger exceeds the requests of pneumatic tools with a margin, then the pressure switch is faulty. We either repair it or replace it with a new one.

Air flow rate is not correct

This malfunction occurs as a result of a gas leak in the high pressure system or a clogged air intake filter. Air leakage can be nullified by pulling all butt joints and wrapping with sealing tape.

Sometimes it happens that when draining condensate from the receiver, they forget to completely close the outlet cock, which also leads to a gas leak. This problem can be easily solved by tightly closing the valve. If the dust filter is clogged, clean it, or even better, replace it with a new one.

Most of the above malfunctions can be avoided by correctly carrying out the first start-up and running-in of the mechanisms, as well as by performing regular maintenance work.

Timely maintenance ensures the performance of the unit

In order for the device to work properly for a long time, you should start the recommended service at early stages operation. Experts recommend the following actions from the moment of purchase:

When opening the transport package, the presence of a passport for the installation is controlled, technical documentation and compliance with the factory inventory of component parts.
Before the first start of the engine, the oil level is checked on the dipstick and, if necessary, topped up to the recommended mark. Oil should be filled in recommended by the manufacturer and specified in the technical documentation. For better spreading of the lubricant and checking for proper operation, let the compressor idle for 10 minutes.
In the absence of comments, the pneumatic tool is connected to the compressor unit and work begins. Note: it is undesirable to supply power to the supercharger if there is excess pressure in the receiver.
Try to keep a record of the compressor running time and after 500 hours of operation, change the oil to a new one. To do this, the flange cover of the crankcase is removed, mining is drained and accumulated contaminants are cleaned. Only after that fresh grease is poured.
Clean the air inlet filter weekly.

After 16 hours of operation, moisture is drained from the receiver using the outlet cock. Manufacturers also recommend cleaning every six months. inner surface balloon using special tools.
At the end of the work, the compressor unit is disconnected from the supply network, and air is bled from the high-pressure system.
If the blower has not been used long time, before start-up, it is necessary to clean and lubricate the contact pads of the air valve.
Non-current-carrying metal parts must be grounded. As a rule, manufacturers bring the grounding conductor into the Euro plug. And you only need to ground the corresponding contact in the socket into which the compressor unit is connected.

Timely observance of these simple requirements will make it possible to keep the mechanism in good condition. Such a time-consuming procedure as do-it-yourself compressor repair will be required extremely rarely. Proper grounding will avoid problems with electrical part devices. Regular replacement of oil and cleaning filters will prevent premature wear of rubbing parts.

Good afternoon. A big request to help those who faced a similar problem. Our company has been repairing tools for 5 years, and we have not encountered such a problem before, and now 2 compressors with the same problem. The electric motor is serviceable, the capacitor is also serviceable, for verification there are all devices that can determine the capacitance of the capacitor, and the exact resistance of the windings. The point is in the mechanical part, the compressor pumps up to 4 atmospheres, and the flywheel jams, as if the bypass valve does not work. That is, the pressure from the receiver presses back, and the engine cannot turn the flywheel with such an effort, turn off the compressor, turn the flywheel with great effort, start the engine, it makes one revolution, with the pressure previously pumped up, and stops again, that is, the mechanics jam. The bypass valve is new, they tried to change the piston rings, the same situation, we are at a loss. If anyone has encountered a similar problem, please help with information.

The aunt brought such a compressor, she says the ball is pumping up, but the wheel of the car is not. The pressure gauge on the compressor does not work, I connected my own, for sure, it gives out 0.2 atm. As usual, the hose is intact, which means we check the valves. The inlets, located in the bottom of the piston, are in order, but the outlets, located in the cylinder head, were very surprised. In both cylinders, rubber rings were slipped under the valves, of course, the valves are constantly open and the compressor I just pumped air inside myself without creating pressure. I removed the rings, assembled everything, turned it on, 2 minutes and 3.5 atm on the pressure gauge. Can anyone explain how these rings could get under the valves? by thoughtlessness.

ELITECH TP30G, 30 kW. I suspect that the air supply may be poorly adjusted, because the smell appears very quickly carbon monoxide, when I disassembled the gun, I saw only one adjusting bolt for the hexagon, but I haven’t touched it yet, I’m waiting for your advice, thanks in advance

The automobile compressor is a device that greatly simplifies the process of tire inflation, which was traditionally performed using a hand or foot pump. This unit can operate in automatic mode, has a compact size, and inflation of tires with its help does not require the use of physical effort. Although the autocompressor is no different complex design, some of its nodes may fail over time. In order to repair the device yourself, you need to have an idea of how it works and on what principle it works.

Compressors for pumping wheels are of the membrane type and piston. Both types of devices are designed to compress air and differ from each other not only constructively, but also in the principle of operation.

Membrane devices

Looking at the device car compressor membrane type, it can be understood that the main element of the unit, with which air is compressed, is the membrane. It is made of either rubber or metal.

The membrane autocompressor consists of the following elements:

an electric motor that drives the drive of the compressor unit;

compression chamber, on which 2 valves are installed;
rubber, polymer or metal membrane located in the compression chamber;
a rod connecting the piston to the membrane;
a piston connected to a rod and connecting rod;
connecting rod and crank;
crankcase, which houses the crank mechanism (KShM).

Autocompressor works according to the following principle. The crank converts the rotation of the drive shaft into reciprocating movements of the connecting rod. The one connected to the piston sets it in motion. The piston, moving up and down, sets the membrane in motion with the help of a rod. Moving down, the membrane creates a vacuum in the compression chamber, due to which the intake valve opens. When the latter is opened, the chamber is filled with air. Moving up, the membrane provokes the closing of the intake valve, and the process of air compression begins. When a certain degree of compression is reached, the exhaust valve opens, after which air under pressure enters the hose connected to the tire. When the membrane moves down, a vacuum is again created in the chamber, from which the exhaust valve closes, and the inlet valve opens. Further, the entire process described above is repeated.

Important! Due to the fact that the compression chamber is hermetically separated from the crankcase, the air at the outlet of the apparatus does not have any impurities. In addition, in membrane units, air leakage through seals or piston rings is excluded, which has a positive effect on the performance of the autocompressor.

Piston units

In piston type tire inflation machines the main part is the piston.

This type consists car pump from the following components and parts:

an electric motor that drives the drive of the apparatus;
compression chambers (cylinder) with intake and exhaust valves;
air filter;
a piston having a sealing ring;
KShM, consisting of a connecting rod and a crank;
crankcase, which houses the crankshaft;
pressure gauge, which is designed to monitor the level of tire pressure and can be mounted on a cylinder or hose.

The device works as follows. The KShM is driven by either a gear transmission or a direct drive. It converts the rotational motion of the drive shaft into reciprocating motion, which causes the piston to move up and down. The piston, moving down, creates a vacuum in the cylinder, as a result of which the intake valve opens. Air, passing through the filter and the opened valve, enters the cylinder. Due to the upward movement of the piston, the air in the cylinder is compressed. When a certain pressure level is reached in the compression chamber, the exhaust valve opens, through which the air exits the apparatus. Further, when the piston moves down, the exhaust valve closes, and the intake valve opens, and the cycle repeats.

Common Reciprocating Compressor Problems

Since the design of membrane autocompressors differs significantly from the piston device, some breakdowns of these devices will be characteristic only for a certain type of units.

The most common malfunctions of piston autocompressors that you can fix with your own hands include the following:

the device does not turn on;
the engine of the unit works, but the air does not pump;
the device does not create the necessary pressure;
the compressor turns off by itself.

The device does not turn on

Tire inflation compressors have power cable(s) for connection to a 12 V power source. Some models of devices are connected to the car's cigarette lighter, and some - to the battery.

If the electric pump does not turn on, then first check the power cables for damage. They can be “ringed out” by a tester. Also, if the compressor is connected to the cigarette lighter, then you need check the integrity of the fuse installed in the plug. If a fuse is blown, it must be replaced.

Advice! Most often, owners of Tornado auto pumps face a blown fuse. Therefore, before connecting the device to the cigarette lighter, you must check the voltage in the latter.

AT last resort, the unit may not turn on due to failure of the electric motor. Most often, the motor windings burn out due to overheating. It is easier to buy a new autocompressor, since repairing the car compressor engine will cost 80% of the cost of a new device.

The engine of the unit runs, but the air does not pump

If, when the device is turned on, the sound of a running engine is heard, but air does not come out of the hose, then in order to diagnose the unit, you have to parse it:

unscrew the 4 screws holding the crankcase cover;

also unscrew the 4 screws mounted on the piston head;

remove the cylinder head.

A valve is installed in the cylinder head, which is a common reason that the device does not pump. To eliminate the malfunction, it is necessary to remove the seal and the disk with the valve from the piston head.

Under the valve is a small sealing ring which may wear out over time. When it is worn, the valve does not fit snugly and lets air through. As a result, the compression of the latter does not occur. Also, sometimes this ring can be displaced from its seat. If this happens, the valve will also fail to close. Often the valve plate simply breaks. In this case, it must be replaced. This part, like other spare parts, can be purchased in online stores.

Another reason that the device does not pump may be loose screw, with which the crank is fixed to the motor shaft.

If the screw is loosened, then the motor shaft will rotate, and the crankshaft will remain stationary.

The device does not create the necessary pressure

If, when trying to inflate the tires, it is not possible to achieve the necessary pressure, then the cause of the problem may be, as in the previous case, the valves. Under them, various contaminants can accumulate, interfering with a good fit. To repair a tire inflation compressor, you will need disassemble the piston head and clean all the parts well from accumulated dirt.

Sometimes insufficient air pressure at the inlet from the unit may be due to O-ring deformation dressed on the piston.

To remove the piston, you need to remove the sleeve jacket and the sleeve itself.

Piston sealing ring may be deformed due to overheating of the unit. To align the ring, it must first be softened. Either thinner 646 or WD-40 can be used for this purpose. After the ring becomes soft and pliable, it should be leveled, the sleeve and jacket should be put in place. You can check whether the piston in the sleeve moves correctly by turning the engine shaft.

The compressor spontaneously turns off

Some models of autocompressors have overheating protection. For this reason, the device may turn off spontaneously, for example, when long work. But overheating of the unit can also be caused due to factory defects, especially in inexpensive models. There is a flaw in poor fit of the device sleeve to the shirt. In this case, heat removal from the piston block is reduced and, as a result, the piston head and engine overheat.

In this case, the repair of an automobile pump will consist in eliminating the gap between the sleeve and the jacket (you can use thin sheet aluminum or thermal paste). Thin sheet aluminum can be "mined" by cutting an ordinary beer can. Aluminum should be wrapped around the sleeve, and tightly inserted into the shirt. After these actions, heat transfer will improve, and the compressor will stop spontaneously turning off.

Malfunctions of membrane autocompressors

Diaphragm autocompressors break very rarely. Although they are characterized by some breakdowns inherent in piston apparatus: damage power cable or blown fuse in the plug used to connect to the cigarette lighter.

But still, the main element of the tire inflation apparatus that can fail is membrane. Most often, it is made of rubber or other plastic material, which, when low temperatures coarsens and becomes inelastic. If such an autocompressor is turned on at a low ambient temperature, then the membrane will simply break. In this case, the repair of an automobile compressor of this type will be to replace the membrane.

How to change the pressure gauge in the compressor

Replacing the pressure gauge on the car compressor will be required if it fails. The measuring device can be installed separately from the machine, on a hose, or on the cylinder head.

If the pressure gauge shows incorrect values or does not work at all, it should be unscrewed and buy similar, with appropriate thread and scale.

Advice! In order not to be mistaken when buying a new pressure gauge, it is recommended to take it with you and ask the seller to pick up an analogue.

In some cases, finding the right device can be difficult. It is easy to get out of this situation: purchase a pressure gauge for a car compressor and tee with matching thread. Attach a manometer with a tee to the end of the hose as shown in the following photos.

Advice! It is recommended to purchase a pressure gauge with a valve installed on it. It will be useful if the tire pressure is exceeded. To deflate the wheel a little, you only need to press the pressure gauge button.

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