MAIP
MAXIMUM ALLOWABLE INTERNAL PRESSURE
 

 

MAXIMUM ALLOWABLE INTERNAL PRESSURE (MAIP) 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

*This table predicts the maximum allowable internal pressure (MAIP) in a borosilicate glass tube. The tube must be annealed and free of surface imperfections, scratches, abrasions, seeds, etc. 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. 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. By David Wright and Michael Wheeler, Arizona State University 1/2002