RathGibson

Bursting Pressure Data

Reference Tool

Pressure Calculator

This calculator uses Barlow's Formula, the standard engineering relationship between internal pressure and tube dimensions, to estimate two figures for a given tube size.

How it works

Enter the tube's outside diameter, wall thickness, and material strength, then choose a working safety factor. The calculator returns:

Theoretical Working Pressure

A conservative operating limit, calculated using your selected safety factor.

Theoretical Bursting or Yielding Pressure

The theoretical failure point, with no safety margin applied (SF = 1).

Which failure mode the bursting/yielding result represents depends on which strength value you enter: use ultimate tensile strength to estimate bursting pressure, or yield strength to estimate the pressure at which permanent deformation begins. See the Bursting Pressure Data chart for minimum strength guidance by alloy.

Source: Machinery's Handbook 25, p. 268, and ASTM A370 A2.3.4.

Example

For a 1/2" OD (0.5) tube with a 0.035" wall and a minimum ultimate tensile strength of 75,000 psi, entering those values with a working safety factor of 2 returns a working pressure of 5,250 psi and a bursting pressure of 10,500 psi — matching the corresponding row in the chart above.

Calculator

Theoretical Pressure Calculator

OD (in) (in)
Wall (in) (in)
Strength Factor
Ultimate tensile strength for bursting, or yield strength for yielding.
 (psi)
Safety Factor (working)  
Safety Factor (bursting) 1  
This OD and wall combination doesn't match a standard RathGibson tube size. Results are still calculated below — double-check your dimensions against the spec chart.
   
Theoretical Working Pressure (selected SF) (psi)
Theoretical Bursting or Yielding Pressure (SF=1) (psi)
Spec Minimum Requirements

Bursting Pressure Data

 
OD (in)OD (mm)Wall (in)Wall (mm)GaugeBurst Pressure (psi)
1/8 (0.125) 3.2 0.020 0.51 25 24,000
0.028 0.71 22 33,600
0.035 0.89 20 42,000
3/16 (0.188) 4.8 0.020 0.51 25 16,000
0.028 0.71 22 22,400
0.035 0.89 20 28,000
1/4 (0.250) 6.4 0.020 0.51 25 12,000
0.028 0.71 22 16,800
0.035 0.89 20 21,000
0.049 1.25 18 29,400
0.065 1.65 16 39,000
0.083 2.11 14 49,800
5/16 (0.313) 7.9 0.020 0.51 25 9,600
0.028 0.71 22 13,440
0.035 0.89 20 16,800
0.049 1.25 18 23,520
0.065 1.65 16 31,200
0.083 2.11 14 39,840
3/8 (0.375) 9.5 0.020 0.51 25 8,000
0.028 0.71 22 11,200
0.035 0.89 20 14,000
0.049 1.258 18 19,600
0.065 1.65 16 26,000
0.083 2.11 14 33,200
1/2 (0.500) 12.7 0.020 0.51 25 6,000
0.028 0.71 22 8,400
0.035 0.89 20 10,500
0.049 1.25 18 14,700
0.065 1.65 16 19,500
0.083 2.11 14 24,900
0.095 2.41 13 28,500
5/8 (0.625) 15.9 0.020 0.51 25 4,800
0.028 0.71 22 6,720
0.035 0.89 20 8,400
0.049 1.25 18 11,760
0.065 1.65 16 15,600
0.083 2.11 14 19,920
0.095 2.41 13 22,800
3/4 (0.750) 19.1 0.020 0.51 25 4,000
0.028 0.71 22 5,600
0.035 0.89 20 7,000
0.049 1.25 18 9,800
0.065 1.65 16 13,000
0.083 2.11 14 16,600
0.095 2.41 13 19,000
0.109 2.77 12 21,800
7/8 (0.875) 22.2 0.020 0.51 25 3,429
0.028 0.71 22 4,800
0.035 0.89 20 6,000
0.049 1.25 18 8,400
0.065 1.65 16 11,143
0.083 2.11 14 14,229
0.095 2.41 13 16,286
0.109 2.77 12 18,686
1 (1.000) 25.4 0.020 0.51 25 3,000
0.028 0.71 22 4,200
0.035 0.89 20 5,250
0.049 1.25 18 7,350
0.065 1.65 16 9,750
0.083 2.11 14 12,450
0.095 2.41 13 14,250
0.109 2.77 12 16,350
0.120 3.05 11 18,000
1-1/8 (1.125) 28.6 0.028 0.71 22 3,733
0.035 0.89 20 4,667
0.049 1.25 18 6,533
0.065 1.65 16 8,667
0.083 2.11 14 11,067
0.095 2.41 13 12,667
0.109 2.77 12 14,533
0.120 3.05 11 16,000
1-1/4 (1.250) 31.8 0.028 0.71 22 3,360
0.035 0.89 20 4,200
0.049 1.25 18 5,880
0.065 1.65 16 7,800
0.083 2.11 14 9,960
0.095 2.41 13 11,400
0.109 2.77 12 13,080
0.120 3.05 11 14,400
1-3/8 (1.375) 34.9 0.035 0.89 20 3,818
0.049 1.25 18 5,345
0.065 1.65 16 7,091
0.083 2.11 14 9,055
0.095 2.41 13 10,364
0.109 2.77 12 11,891
0.120 3.05 11 13,091
1-1/2 (1.500) 38.1 0.035 0.49 20 3,500
0.049 1.25 18 4,900
0.065 1.65 16 6,500
0.083 2.11 14 8,300
0.095 2.41 13 9,500
0.109 2.77 12 10,900
0.120 3.05 11 12,000
1-5/8 (1.625) 41.3 0.035 0.49 20 3,229
0.049 1.25 18 4,520
0.065 1.65 16 5,996
0.083 2.11 14 7,657
0.095 2.41 13 8,764
0.109 2.77 12 10,055
0.120 3.05 11 11,070
1-3/4 (1.750) 44.5 0.035 0.89 20 3,000
0.049 1.25 18 4,200
0.065 1.65 16 5,571
0.083 2.11 14 7,114
0.095 2.41 13 8,143
0.109 2.77 12 9,343
0.120 3.05 11 10,286
2 (2.000) 50.8 0.035 0.89 20 2,625
0.049 1.25 18 3,675
0.065 1.65 16 4,875
0.083 2.11 14 6,225
0.095 2.41 13 7,125
0.109 2.77 12 8,175
0.120 3.05 11 9,000
2-1/8 (2.125) 54.0 0.049 1.25 18 3,459
0.065 1.65 16 4,588
0.083 2.11 14 5,859
0.095 2.41 13 6,706
0.109 2.77 12 7,694
0.120 3.05 11 8,471
2-1/4 (2.250) 57.2 0.049 1.25 18 3,267
0.065 1.65 16 4,333
0.083 2.11 14 5,533
0.095 2.41 13 6,333
0.109 2.77 12 7,267
0.120 3.05 11 8,000
2-1/2 (2.500) 63.5 0.049 1.25 18 2,940
0.065 1.65 16 3,900
0.083 2.11 14 4,980
0.095 2.41 13 5,700
0.109 2.77 12 6,540
0.120 3.05 11 7,200
2-5/8 (2.625) 66.7 0.049 1.25 18 2,800
0.065 1.65 16 3,714
0.083 2.11 14 4,743
0.095 2.41 13 5,429
0.109 2.77 12 6,229
0.120 3.05 11 6,857
2-3/4 (2.750) 69.9 0.049 1.25 18 2,673
0.065 1.65 16 3,545
0.083 2.11 14 4,527
0.095 2.41 13 5,182
0.109 2.77 12 5,945
0.120 3.05 11 6,545
3 (3.000) 76.2 0.049 1.25 18 2,450
0.065 1.65 16 3,250
0.083 2.11 14 4,527
0.095 2.41 13 4,750
0.109 2.77 12 5,450
0.120 3.05 11 6,000
3-1/2 (3.500) 88.9 0.065 1.65 16 2,786
0.083 2.11 14 3,557
0.095 2.41 13 4,071
0.109 2.77 12 4,671
0.120 3.05 11 5,143
4 (4.000) 101.6 0.065 1.65 16 2,438
0.083 2.11 14 3,113
0.095 2.41 13 3,563
0.109 2.77 12 4,088
0.120 3.05 11 4,500
6 (6.000) 152.4 0.083 2.11   2,100
0.109 2.77   2,700
8 (8.000) 203.2 0.109 2.77   2,000
Tech Info