Air: Source of the industrial gas products oxygen, nitrogen and argon

Atmospheric Pressure  at  Site Elevation

  Feet  

  Meters  

  psia  

Atm

Bar (a)

kPa kg/cm2

 In Hg 

 Mm Hg 

0

0

14.7

1.00 1.013 101 1.03

29.9

760

328 100 14.5 0.99 1.000 100 1.02 29.5 752

500

150

14.4

0.98 0.994 99.4 1.01

29.4

747

656 200 14.3 0.97 0.988 98.8 1.01 29.2 743

1000

300

14.2

0.96 0.976 97.6 1.00

28.9

734

1312 400 14.0 0.95 0.964 96.4 0.98 28.5 725

1500

450

13.9

0.94 0.956 95.6 0.98

28.3

719

2000

600

13.7

0.93 0.939 93.9 0.96

27.8

706

2500

750

13.4

0.91 0.923 92.3 0.94

27.3

694

3000

900

13.2

0.89 0.906 90.6 0.92

26.8

681

3500

1070

12.9

0.88 0.888 88.8 0.91

26.3

668

4000

1220

12.7

0.86 0.871 87.1 0.89

25.8

655

4500

1370

12.4

0.85 0.858 85.8 0.87

25.4

645

5000

1520

12.2

0.83 0.842 84.2 0.86

24.9

633

5500

1680

12.0

0.81 0.825 82.5 0.84

24.4

620

6000

1830

11.8

0.80 0.811 81.1 0.83

24.0

610

6500

1980

11.5

0.78 0.794 79.4 0.81

23.5

597

7000

2130

11.3

0.77 0.781 78.1 0.80

23.1

587

7500

2290

11.1

0.76 0.767 76.7 0.78

22.7

577

8000

2440

10.9

0.74 0.750 75.0 0.76

22.2

564

8500

2590

10.7

0.73 0.737 73.7 0.75

21.8

554

 
Impact of elevation on air separation plant capacity and power

To provide a pre-determined amount of air to an air separation processes (as measured by weight or standard volumes such as SCF or Nm3 ) air compressors that will be operated at higher elevations must process greater physical volumes of air (actual cubic feet or actual cubic meters) than would be required if the plant were located near sea level. 

At higher elevations, more power is required to deliver the same amount of compressed air (actual weight or volume) to the air separation process.  This is  because the pressure ratio across the air compressor will be greater at higher elevations when the air feed is compressed to the design operating pressure as measured in absolute pressure units.      

This table can be used to determine the required inlet capacity for new air compression equipment.  It can also be used, with the aid of general compressor performance relationships or specific compressor performance curves, to estimate changes in performance for relocated air compression equipment.   

 

Universal Industrial Gases, Inc.
2200 Northwood Ave. Suite 3
Easton, Pennsylvania 18045-2239 USA

Phone (610) 559-7967 Fax (610) 515-0945

All material contained herein Copyright 2003 / 2004  UIG.