China 3bar Low Pressure Oil Injected Industrial Rotary 37kw 50HP Screw Air Compressor for Industrial Gases Nitrogen

Product Description

Product Description

Product features of low pressure screw air compressor:

1. Adopt large rotor and low speed to ensure the high performance of the machine;
2. Increase oil and gas separation equipment to ensure that the export oil content is ≤3ppm;
3. The air source of the low-pressure screw air compressor is clean, which reduces the number of cleaning nozzles of texturing machines and other equipment, and improves the quality of the finished product;
4. The heat dissipation area of the oil cooler is increased by more than 30% to ensure normal operation in summer without over-temperature;
5. Independently design the internal pressure ratio of the host to ensure a better specific power;
6. Intelligent control system, automatically adjust the exhaust volume according to the customer’s usage (frequency conversion model).
7. For the texturing industry, ensure long-term continuous operation, set fault warnings, and do not stop immediately, so that customers are fully prepared for shutdown;
8.  Adopting dual air outlet design, the air outlet temperature can be adjusted according to climate changes, meeting customer needs to a greater extent, and achieving high efficiency and energy saving at the same time.

1. Efficient airend
There is no intermediate transmission, so there is no energy loss; direct drive increases reliability and reduces maintenance costs; large rotors run at low speeds, with higher efficiency, lower noise, lower vibration, and lower energy consumption.

2. High-quality independent oil pump forced lubrication design
(1) Forced lubrication with independent oil pump;
(2) Ensure that there is sufficient fuel injection and a better air-fuel mixture ratio under extremely low exhaust pressure (2kg).

3. Increase customized oil and gas separation system
Increase the customized oil and gas separation system to ensure the ultimate oil and gas separation effect and ensure that the oil content of the air is less than 3ppm.

Product Parameters

Low-pressure permanent magnet variable frequency air compressor parameters:

Model Volume flow(m3/min) Pressure(Mpa/bar) Power(kW) Noise(DB) Outlet diameter Dimension(mm) Weight(kg)
DHH37LM 10.0 0.3/3 37 65 G2 2000*1120*1590 1180
9.6 0.4/4
8 0.5/5
DHH45LM 15.1 0.2/2 45 65 G2 2100*1677*1892 2500
12.2 0.4/4
9.3 0.5/5
DHH55LM 22 0.2/2 55 70 DN150 2800*1860*1900 3200
15.61 0.3/3 DN100 2100*1677*1892 2600
15.48 0.4/4
12.00 0.5/5
DHH75LMH 29.5 0.2/2 75 70 DN150 2800*1860*1900 3200
21.5 0.3/3
21.0 0.4/4
16.1 0.5/5 DN65 2400*1630*1980 1850
DHH90LMH 31.0 0.2/2 90 72 DN150 2800*1860*1900 3300
28.8 0.3/3
21.0 0.5/5
DHH110LMH 37.0 0.2/2 110 72 DN200 2900*2100*2150 4800
33.0 0.3/3
28.5 0.4/4
DHH132LMH 47 0.2/2 132 78 DN200 2900*2100*2150 4950
43.8 0.3/3
32.5 0.4/4
28.3 0.5/5 DN80 2800*1828*2150 3600
DHH160LMH 55.7 0.2/2 160 78 DN300 4500*2200*2200 6800
49.4 03/3 DN200 2900*2100*2150 5100
43.0 0.4/4
DHH185LMH 60.0 0.3/3 185 78 DN200 4500*2200*2200 6900
43.0 0.5/5

Parameters of two-stage low-pressure screw air compressor:

Model Volume flow(m3/min) Power(kW) Noise(DB) Outlet diameter Dimension(mm) Weight(kg)
0.45~0.5mpa 0.55mpa
DHH30LDM 7.06 6.95 30 68 G2 1600*1060*1470 1338
DHH37LDM 10.0 9.20 37 68 G2 1600*1060*1470 1438
DHH45LDM 11.98 11.65 45 70 DN65 2400*1630*1980 1734
DHH55LDM 15.57 15.48 55 70 DN65 2400*1630*1980 1980
DHH75LDM 18.51 18.32 75 72 DN65 2400*1630*1980 2080
DHH90LDM 22.92 22.51 90 72 DN80 2800*1828*2150 4700
DHH110LDM 26.81 26.11 110 72 DN80 2800*1828*2150 4850
DHH132LDM 32.5 31.98 132 78 DN80 2800*1828*2150 4850
DHH160LDM 41.11 40.68 160 78 DN100 3000*1900*2190 5000
DHH185LDM 43.88 43.52 185 78 DN100 4360*2150*2258 7200
DHH220LDM 55.31 55.06 220 80 DN200 4360*2150*2258 7200
DHH250LDM 60.31 60.12 250 80 DN200 4360*2150*2258 7500


Company Profile

We’re professional compressor factory since 1996. Germany Standard and 13 years exporting experience help us won more than 50 loyal foreign agents. 

Our products line are complete,main products as below.
1. Ordinary fixed speed air compressor

2. Energy saving series:
VSD screw air compressor
Permanent magnet VSD screw air compressor
Double stage PM VSD screw air compressor

3. Oil free series:
Oil free water lube screw air compressor
Dry oil free type
Oil free scroll type

4. Low pressure series:
3-5bar, main for textile industry
0.4-1.5 bar,main for waste water treatment

5. 16bar-30bar special for laser cutting industry

6. After-treat equipment
Refrigerated air dryer
Desiccant air dryer
High efficiency pipeline filter

And all the compressor parts.

Packaging & Shipping

Why choose us


Q1. Are you trading company or manufacture ?

A: We are professional manufacture of screw air compressor of HangZhou(Close to ZheJiang ), China, more than 24 years.

Q2. How long is the delivery time ?
A: For standard voltage ,15 working days. Non-standard ,please contact our sales.

Q3. What’s payment term ?
A: T/T, L/C, D/P, Western Union, Paypal, Credit Card, and etc. Also we could accept USD, RMB, Euro and other currency.

Q4. How about your after-sales service ?
A: 1.Provide customers with installation and commissioning online instructions.
  2. Well-trained engineers available to overseas service.
  3.Worldwide agents and after service avaiable.arrange our engineers to help you training and installation.

Q5. How about your warranty?
A: One year for the whole machine and 2 years for screw air end, except consumable spare parts.

Q6. Do you have any certificate ?
A: Yes, per different customer’s market need ,we can offer CE ,ISO etc certificate.

Q7. What about the maintenance ?
A: First maintenance need to be done after 500Hours, and then every 2000-3000 hours to do the normal maintenance, and consider the actual environment.

Q8. How do you control quality ?
A: 1.The raw materials are strictly inspected
      2. Some key parts are imported from overseas
      3.Each compressor must pass at least 5 hours of continuous testing before leaving the factory.

Q9. Do you offer OEM service ?
A: Yes.Both OEM & ODM service can be accepted.

Q10.How long could your air compressor be used?
A: Generally, more than 10 years.

The Air Compressor Is a Versatile Tool

The Air Compressor is 1 of the most versatile tools in any garage or workshop. It is easy to use and can perform a variety of tasks, from jackhammering to drilling. These machines are available in a wide variety of sizes and types, making it an excellent choice for a variety of situations. With a single motor, you no longer need separate motors for each tool. Its lightweight, compact design makes it easy to handle, and the single motor also reduces wear on parts.


Oil-injected air compressors require a large amount of lubricant, which needs to be added to the sump regularly to maintain optimum performance. As there are many types of industrial fluids, a well-intentioned maintenance technician may add the wrong lubricant to the compressor. If this happens, the compressor will become incompatible with the lubricant, resulting in excessive carryover and the need to flush and replace downstream air treatment components.
Typically, the G 110-250 oil-injected rotary screw compressor from Atlas Copco provides reliable compressed air, preventing costly downtime. The G110-250 oil-injected rotary screw compressor is highly reliable and durable, enabling it to function in temperatures up to 46degC/115degF. Despite the oil-injected air compressor’s robust design, this unit requires very little on-site installation, and it features simple operation.
The primary advantage of oil-injected air compressors is the reduced cost of running. The cost of oil-free compressors is less than half of that of oil-injected ones, and it will require fewer maintenance costs in the long run. Moreover, the oil-free system is more environmentally friendly than oil-injected air compressors. But the drawbacks of oil-injected air compressors are substantial, too. It can contaminate finished goods and cause a significant financial risk for the manufacturer.
An oil-injected rotary screw air compressor offers several advantages over its counterpart. First, it features an innovative vertical design with variable-speed drive, allowing it to run more efficiently. Second, oil-injected air compressors reduce energy consumption by up to 50% compared to non-oil-injected air compressors. They also have a thermostatic valve, allowing them to maintain an optimum temperature. Thermostatically-regulated oil coolers allow the compressor to run more quietly.


What is an oil-free air compressor? The name refers to a type of air compressor that does not contain oil in the compressor chamber. Oil-free air compressors still use oil for various purposes, including lubricating the moving parts and managing waste heat. However, many people do not realize that their air compressor still requires oil for proper functioning. This article will explore why this type of air compressor is preferable for many users.
First of all, oil-free air technology has many benefits. For one, it reduces the energy cost involved in filtering air, and it minimizes leaks. Moreover, it also reduces the oil costs associated with compressor refills. And finally, it reduces the risks of contamination. Oil-free air technology is the future of compressed air. If you’re looking for an oil-free air compressor, here’s what to look for in your search.
Depending on the purpose of your air compressor, it may be beneficial to invest in an oil-free air compressor. Oil-lubricated air compressors are generally more durable than their oil-free counterparts, but they may cost twice as much. You should still consider the cost of ownership before purchasing an oil-free compressor. The oil-free models can be easier to transport, and they are more powerful. Moreover, they’re quieter than oil-lubed models.
An oil-free air compressor also means less maintenance, as it doesn’t need oil to work. This type of air compressors also features fewer moving parts, which means fewer places for problems to develop. All oil-free air compressors are manufactured to meet ISO Class 0 and 1 air purity standards. They also have less noise and vibration compared to their oil-based counterparts. So, why not choose an oil-free air compressor for your business?


When choosing a gas-powered air compressor, it’s important to consider the advantages of gasoline. This energy source can power a large air compressor without electricity. However, this type of air compressor lacks electrical hookup, so you’ll need to run an extension cord if you need to use it at a distance. However, gas compressors are able to function with just a gas tank. This makes them ideal for medium to heavy-duty industrial applications.
Another important consideration when choosing a gas air compressor is its size. Larger compressors are typically larger than portable ones and require more space. This makes them easier to transport and operate on the go. However, if you’re not sure which type of air compressor is best for you, consider the gas-powered versions. While they may be lighter, they don’t run as smoothly as their electric counterparts. Gasoline-powered compressors are not as portable as their electric counterparts and require proper maintenance.


Electricity in an air compressor is not cheap. A 25 HP air compressor runs for 10 hours each day, 5 days a week. The motor in these machines consumes 746 watts per hour. To find out how much electricity the equipment uses, multiply the wattage by the running time. For example, if the compressor runs for 3 hours, then it will use 1.9 kilowatt hours of electricity. To determine how much electricity an air compressor uses per day, you can calculate the kilowatt hours and multiply the number by the utility rate. Considering this, you can determine the cost of running your air compressor once per month.
The cost of operating an air compressor depends on the type of compressor. Electric air compressors are often silent and can run without any maintenance. These tools can be left unattended for up to 4 thousand hours before requiring repair. Electric air compressors require higher power for higher pressure, so you should plan accordingly. Whether or not you need a maintenance visit is up to you, but the benefit of not having to spend a fortune on repairs is priceless.
Although compressed air is not an energy-efficient source, its use in a variety of applications may save you money and kilowatts. Since an air compressor uses power when it is running, the cost is lower than the cost of operating a power tool. If you plan to use your air compressor for a long time, make sure that it is maintained properly. Proper care will save you money and power, and you may even be able to get an extended warranty if the compressor breaks down.

Variable frequency drive

The main purpose of a variable frequency drive (VFD) in an air compressor is to reduce energy consumption in the process of compression. A single motor drag system cannot adjust its speed continuously according to the weight of the load. By applying frequency control to the compressor, the power consumption can be reduced while maintaining the same pressure level. Therefore, a VFD is an excellent choice for compressors. Its benefits are numerous.
A VFD can also monitor the temperature of the motor and send error signals if the motor is running too hot or too cold. This eliminates the need for a separate sensor to monitor the oil pressure. These functions are useful not only in lowering energy consumption, but also in improving the performance of an application. Moreover, a VFD can monitor additional variables such as temperature and motor speed. Hence, it is a useful investment.
When using a VFD, it is crucial to choose the right motor. The speed of the compressor should be within the maximum starting limit of the motor. The air tank may be of any size, but a constant pressure limit is required to keep the VFD running within the service factor of the motor. In addition to a VFD, a master controller should also include a remote pressure set point and a PID card for a master controller. The transmitter should incorporate all useful data from the VFD, including the speed and the oil temperature. The VFD must be tested before it is integrated with the master control. It should be tested for min and max speed, temperature, and current within the expected range.
The use of a VFD in an air compressor has many benefits. One of the most notable is the reduction in power consumption. Fixed-speed compressors run on set points of 6 to 7 bar. An extra bar of compression uses 7 percent of energy. This energy is wasted. A VFD-powered air compressor can also increase the life span of compressor parts. It is 1 of the best investments in your compressor. So, why wait any longer?

China 3bar Low Pressure Oil Injected Industrial Rotary 37kw 50HP Screw Air Compressor for Industrial Gases Nitrogen  China 3bar Low Pressure Oil Injected Industrial Rotary 37kw 50HP Screw Air Compressor for Industrial Gases Nitrogen

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