How much pressure is the air source used in the machining workshop?

The pressure of the air supply used in the machining shop is usually 0.5~0.8 MPa(5~8 bar) however, the specific pressure value should be determined according to the equipment type, process requirements and safety specifications. The following is a detailed analysis:

air supply pressure requirements for 1. common equipment

1. pneumatic tools
   • air wrench/screwdriver: Usually required 0.6~0.7 MPa, Too low pressure will cause insufficient torque, too high may damage the tool or workpiece.
   • Pneumatic grinding wheel/grinding machine: High pressure demand, generally 0.7~0.8 MPa to ensure cutting or grinding efficiency.
   • Spray gun (painting, sand blasting): Wide pressure range, 0.4~0.7 MPa it can be adjusted according to the spraying material and effect.
2. CNC Machine Tools and Automation Equipment
   • pneumatic Clamp/Chuck: Usually required 0.5~0.6 MPa pressure stability is the key, and excessive fluctuations may cause the workpiece to loosen or decrease the machining accuracy.
   • Spindle cooling and purging: Some high-end machine tools need 0.6~0.8 MPa the clean dry air prevents chips from entering the spindle or optical system.
3. pneumatic conveying system
   • material handling (e. g. aluminum shavings, plastic pellets): Pressure requirements vary depending on the conveying distance and material characteristics, short-distance conveying may only require 0.3~0.5 MPa, long distance or complex pipeline needs 0.6~0.8 MPa.

Basis of 2. pressure selection

1. equipment Manufacturer's Specification
   all pneumatic equipment will be marked with the rated working pressure range (e. g. 0.5~0.7 MPa), out of range may cause performance degradation or damage. For example, a brand of pneumatic wrench explicitly requires that the input pressure should not be less 0.6 MPa otherwise, the torque cannot reach the nominal value.

2. Process accuracy requirements

   • precision machining (e. g. optical components, semiconductors): Required 0.6~0.8 MPa the stable gas source is matched with precision filter (0.01μm grade) and dryer (dew point ≤-40 ℃) to avoid tiny particles or water vapor affecting the product yield.
   • General machining: 0.5~0.6 MPa it can meet the demand, but it is necessary to ensure that the pressure fluctuation is ≤ ± 0.05 MPa, otherwise it may cause processing vibration or dimensional deviation.

3. Pipeline Loss and Gas Tank Configuration

   • pipe length and diameter: Long distance or thin pipeline will cause pressure loss, which needs to be compensated by increasing the initial pressure. For example, when the flow rate of 100 m long and DN25 pipeline is 5m & sup3;/min, the pressure loss is about 0.05 MPa.
   • Gas tank capacity: Large-capacity gas storage tank (such as 2m & sup3;) can buffer the peak gas consumption, reduce pressure fluctuations, and allow the air compressor to operate at a lower pressure (such 0.55 MPa to meet the demand).

3. Safety and Energy Efficiency Optimization

1. high risk of stress
   • accelerate equipment wear: pneumatic tool seals are easy to age under high pressure, and their service life is shortened by 30% to 50%.
   • Increase energy consumption: for every 0.1 MPa increase in the output pressure of the air compressor, the energy consumption increases by about 7% ~ 10%.
   • Safety hazard: high-pressure gas leakage may cause explosion or personal injury, need to install the safety valve (set pressure is usually 10% higher than the rated pressure).
2. Effect of low pressure
   • performance degradation of equipment: if the torque of pneumatic wrench is insufficient, the tightening torque of bolts is not up to standard, which may lead to safety accidents.
   • Reduced production efficiency: Insufficient pressure in the pneumatic conveying system will cause material blockage and increase downtime.
3. Optimization recommendations
   • graded gas supply: Set different pressure areas according to equipment requirements (such as 0.7 MPa for high-precision area and 0.5 MPa for ordinary area) and adjust them through pressure reducing valve.
   • intelligent control: Using frequency conversion air compressor + pressure sensor, dynamically adjust the output pressure according to the gas consumption, saving energy by 15% ~ 20%.
   • Regular maintenance: Clean the pipeline rust, replace the aging seal, reduce the pressure loss.

4. actual case reference

• auto parts processing plant:
  • pneumatic wrench: 0.65 MPa
  • CNC machine fixture: 0.55 MPa
  • aluminum chip conveying system: 0.7 MPa
  • through the combination of air storage tank and pressure reducing valve, the outlet pressure of air compressor is set to 0.75 MPa, and the actual gas point pressure is stable at 0.6±0.02 MPa.
• Precision mould workshop:
  • sandblasting machine: 0.7 MPa
  • pneumatic measuring instrument: 0.6 MPa (need to cooperate with three-stage filtration)
  • the air compressor is equipped with a cold dryer with dew point ≤-20 ℃ to ensure that the compressed air quality meets the standard.