The air compressor uses high or low air pressure.

The air pressure used by the air compressor is not as high as possible. The appropriate air pressure should be selected according to actual needs. The core principle is "constant pressure on demand", and the air supply pressure should be reduced as much as possible on the premise of meeting production needs.. Specific analysis is as follows:

disadvantages of 1. high air pressure

1. waste of energy consumption
   the energy consumption and pressure of the compressed air system are nonlinear, and the higher the pressure, the faster the energy consumption increases. For example:

   • the gas supply pressure is increased from 0.7MPa to 0.8MPa (an increase of 14%), and the energy consumption is increased by 8%-10%;
   • if it is blindly increased to 0.9MPa (up 28%), the energy consumption will increase by 18%-22%.
     According to industry data, for every 0.1MPa gas supply pressure reduction, system energy consumption can be reduced by 5%-8%.

2. Accelerated equipment aging
   high pressure will aggravate the wear of the sealing ring of the pipe joint and the valve core of the pneumatic component, resulting in the increase of the leakage rate, forming a vicious circle of "high pressure & rarr; high leakage & rarr; higher pressure", further increasing the energy consumption and maintenance cost.

3. Affect product quality
   some precision equipment (such as chip packaging equipment) is sensitive to pressure fluctuations, and excessive pressure may cause damage to parts or product scrap.

Applicability of 2. low air pressure

1. meet most equipment needs
   the actual gas demand of most enterprises is far lower than the default 0.8MPa:
   • the rated pressure of pneumatic tools (wrench, spray gun) is 0.6-0.7MPa;
   • the demand pressure of packaging machinery and electronic components assembly equipment is even as low as 0.4-0.5MPa.
     Therefore, under the premise of meeting the normal operation of the equipment, reducing the gas supply pressure can significantly save energy.
2. Significant energy saving effect
   take a 2.2kW air compressor as an example. If the pressure is reduced from 0.8MPa to 0.65MPa and the work is 8 hours a day, the electricity cost can be saved by about 1800 yuan a year. If the enterprise has more than one air compressor, the annual savings can reach tens of thousands of yuan.

3. how to determine the optimal supply pressure

1. statistics equipment demand pressure
   comb all pneumatic equipment in the workshop, consult the manual or nameplate, record the "rated working pressure" of each equipment (I. e. the minimum pressure required for normal operation of the equipment), and take the "maximum value" of the rated pressure of all equipment as the basic data.

2. Reserved pressure loss allowance
   when compressed air is transported from the air compressor to the equipment, pressure loss will occur due to pipeline resistance and leakage. A certain margin (usually 0.05-0.1MPa) should be reserved to avoid insufficient pressure of the end equipment. For example:

   • if the maximum demand pressure is 0.6MPa, the pipeline is short and the leakage is small, the optimal gas supply pressure = 0.6MPa + 0.05MPa = 0.65MPa;
   • if the pipeline is long and has many leaks, the optimal pressure = 0.6MPa + 0.1MPa = 0.7MPa.

3. Dynamic testing and adjustment
   set the air supply pressure of the air compressor to the calculated value, start all pneumatic equipment, and check the operating status of the end equipment:

   • if the torque of the pneumatic tool is sufficient, the painting is uniform, and the clamping force of the fixture is normal, the pressure setting is reasonable;
   • if some equipment is "boring" or "Caton", the pressure can be gradually increased (0.02MPa each time) until all equipment operates normally, and the pressure at this time is the final optimal setting value.

4. safeguard measures

1. locking pressure set value
   set the pressure setting permission on the air compressor control panel (only the equipment manager can modify), and post the "optimal pressure value" logo to prevent the operator from increasing the pressure without permission.

2. Reduce pressure loss

   • optimize the pipeline: Replace thin pipe diameter (≤ 25mm) with thick pipe diameter (≥ 32mm) to reduce pipe resistance; shorten pipe length to avoid unnecessary bends and branches.
   • Leak Governance: Check the leakage point with ultrasonic detector every month, and control the system leakage rate below 8%.

3. Zonal constant pressure
   if the demand pressure of equipment in the workshop varies greatly (for example, some equipment needs 0.6MPa and some only 0.4MPa), "regional gas supply" can be adopted ":

   • install the main pipeline at the outlet of the air compressor, and then divide the main pipeline into high pressure area (such as 0.65MPa, for pneumatic wrench and other equipment) and low pressure area (such as 0.45MPa, for precision instruments and other equipment) through the pressure reducing valve;
   • each area is equipped with a pressure gauge separately to monitor the pressure in real time, so as to avoid the pressure in the high pressure area from "stringing" into the low pressure area and causing waste.

4. Regular monitoring and rewinding

   • record the air supply pressure and power consumption of the air compressor every day, compare the energy consumption changes before and after pressure adjustment, and verify the energy saving effect;
   • the demand pressure of the equipment shall be re-counted every quarter (if the equipment is added or replaced, the maximum demand pressure shall be updated), and the optimal setting value shall be adjusted to ensure that the pressure setting always matches the actual demand.