UNIVERSITY of DELAWARE
DEPARTMENT of CHEMISTRY and BIOCHEMISTRY

 

Borosilicate MAIP Table

 

Although the table below gives recommended manufacturer maximum allowable internal pressure of borosilicate tubing, it does not take into consideration the items listed in the paragraph below.
Please read the section labeled “Extremely Important” before pressurizing any glassware. Great care and precaution should be used to prevent explosion and injury.

 

 

Shields and safety glasses are a necessity… not an option.
MAXIMUM ALLOWABLE INTERNAL PRESSURE TABLE   (in atmospheres)

WALL THICKNESS (MM)

 

 

 

 

 

 

 

 

OD

IN

MM

 

0.2

0.4

0.6

0.8

1

1.5

2

3

4

5

6

7

8

9

10

0.6

45

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.8

34

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

27

54

 

 

 

 

 

 

 

 

 

 

 

 

 

2

14

27

41

54

 

 

 

 

 

 

 

 

 

 

 

3

9

18

27

36

45

 

 

 

 

 

 

 

 

 

 

4

7

14

20

27

34

51

 

 

 

 

 

 

 

 

 

5

5

11

16

22

27

41

54

 

 

 

 

 

 

 

 

6

5

9

14

18

23

34

45

 

 

 

 

 

 

 

 

7

4

8

12

16

19

29

39

58

 

 

 

 

 

 

 

8

3

7

10

14

17

26

34

51

 

 

 

 

 

 

 

9

3

6

9

12

15

23

30

45

60

 

 

 

 

 

 

10

3

5

8

11

14

20

27

41

54

 

 

 

 

 

 

11

2

5

7

10

12

19

25

37

49

62

 

 

 

 

 

12

2

5

7

9

11

17

23

34

45

57

 

 

 

 

 

13

2

4

6

8

10

16

21

31

42

52

63

 

 

 

 

14

2

4

6

8

10

15

19

29

39

49

58

 

 

 

 

15

2

4

5

7

9

14

18

27

36

45

54

63

 

 

 

16

2

3

5

7

9

13

17

26

34

43

51

60

 

 

 

17

2

3

5

6

8

12

16

24

32

40

48

56

64

 

 

18

2

3

5

6

8

11

15

23

30

38

45

53

60

 

 

19

1

3

4

6

7

11

14

21

29

36

43

50

57

64

 

20

1

3

4

5

7

10

14

20

27

34

41

48

54

61

 

22

1

2

4

5

6

9

12

19

25

31

37

43

49

56

62

25

1

2

3

4

5

8

11

16

22

27

33

38

44

49

54

Thanks to David Wright and Michael Wheeler for table above - 1/2002 A.S.G.S.

 

*This table predicts the maximum allowable internal pressure (MAIP) in a borosilicate glass tube. The MAIP of a tube can be determined by measuring the outside diameter and wall thickness of the tube and follow the row and column locations to the intersecting pressure. This information is not for flat bottom vessels or others not rated for pressure or vacuum. The pressure is listed in Atmospheres (ATM). 1 Atmosphere equals 14.7 pounds per square inch (PSI). On the above table, a 10mm OD tube with a 1mm wall thickness (labeled yellow) has a MAIP of 14 atmospheres (labeled green). 14 ATM times 14.7 PSI equals 205.8 PSI  MAIP.  For continuous service or long periods it is suggested to use the MOP (maximum operating pressure). I recommend figuring this 20 % below the MAIP. As you can see, when the diameter is increased the MAIP significantly decreases. Glass can be highly unpredictable and therefore these figures are for reference only.
EXTREMELY IMPORTANT-  PLEASE  READ- The information above assumes that the tubing is new, annealed, free of surface imperfections, scratches, abrasions, seeds, etc. If any of the mentioned flaws are present (whether readily noticeable or not) it can greatly reduce the MAIP. Use a fine adjustment regulator and gauge for accurate monitoring. Also when possible use a calibrated relief valve in case of regulator malfunction. 
ALWAYS  use a shield  and safety goggles when pressurizing any glassware!

 

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