5.2.4 Non lubricated air compressors 22.214.171.124 Reciprocating, nonlubricated air compressors substitute low friction or self lubricating materials such as carbon or teflon for piston and packing rings, where the piston is usually supported on wear rings of similar materials. 126.96.36.199 Oil free rotary screw and lobe-type compressors are available, having a design that does not require lubrication in the compression chamber for sealing and lubrication. 188.8.131.52 Centrifugal air compressors are inherently nonlubricated due to their configuration. 184.108.40.206 Generally, nonlubricated compressors have a higher initial cost due to the special design and materials. 220.127.116.11 Nonlubricated reciprocating air compressors also tend to have higher operating costs due to higher maintenance cost associated with shorter valve and ring life. 5.2.5 Regulation of compressed air Regulation of compressed air system shall be as per Standard IPS-E-PR-750 , "Process Design of Compressors". 5.2.6 Compressor selection Compressor selection shall be as per Standard IPS-E-PR-750 , "Process Design of Compressors". In addition the following Process Machineries Standards shall be considered as complementary: IPS-E-PM-100 "Engineering Standard for Design General Requirements of Machineries" IPS-M-PM-170 "Material and Equipment Standard for Centrifugal Compressors for process Services" IPS-G-PM-200 "General Standard for Reciprocating Compressors for Petroleum , Chemical and Gas Industry Services" IPS-M-PM-220 "Material and Equipment Standard for Positive Displacement Compressors, Rotary". 5.2.7 Automatic warning and shutdown systems Air compressor systems will be protected against high temperature, high pressure, low oil pressure and in the case of centrifugal compressors ,excessive vibration and etc. Protective control will include a fault indicator and a manual reset device. 18.104.22.168 An automatic warning and shutdown system should be considered for installation with most air compressors for a complete reliable air system. 22.214.171.124 Compressor shutdown should be scheduled to occur at a preset point after a warning condition is reached. 126.96.36.199 Some conditions, such as low oil pressure or excessive vibration, shall demand immediate shutdown. 188.8.131.52 Protective control systems employing shutdown without indication, which merely drops out
Nov. 1993 IPS-E-PR- 330 11 the holding coil of the motor starter, shall be usually warranted only on very small compressors. 5.2.8 Compressed-air distribution system Any drop in pressure between the compressor and the point of use is an unrecoverable loss. The distribution system is therefore one of the most important elements of the compressed air plant. In planning it, the following general rules should be observed: 184.108.40.206 Pipe sizes should be large enough that the pressure drop between the plot limits of air compression and consumer units does not exceed 10 percent.
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- Summer '16
- Mechanical Engineering, Atmospheric thermodynamics, Water vapor, Psychrometrics, Wet-bulb temperature