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The Standard Pressure for Heat Exchanger Tubes
of Tantalum and Tantalum Alloy (Per ASTM B 521)
Table 1 Min Pressure for Unalloyed Tantalum Tubes (R05200 & R05400), psi |
| t (Wall Thickness) |
D (Outside Diameter) |
0.50" |
0.75" |
1.00" |
1.50" |
| 0.015" |
900 |
600 |
450 |
300 |
| 0.020" |
1200 |
800 |
600 |
400 |
| 0.035" |
2100 |
1400 |
1050 |
700 |
Table 2 Min Pressure for Tantalum Alloy (2.5% Tungsten)Tubes (R05252), psi |
| t (Wall Thickness) |
D (Outside Diameter) |
0.50" |
0.75" |
1.00" |
1.50" |
| 0.015" |
1260 |
840
|
630 |
420 |
| 0.020" |
1680 |
1260
|
840 |
630 |
| 0.035" |
2940 |
1960 |
1470 |
980 |
Table 3 Min Pressure for Tantalum Alloy (10% Tungsten)Tubes (R05255), psi |
| t (Wall Thickness) |
D (Outside Diameter) |
0.50" |
0.75" |
1.00" |
1.50" |
| 0.015" |
2700 |
1800
|
1350 |
900 |
| 0.020" |
3600 |
2400
|
1800 |
1200 |
| 0.035" |
6300 |
4200 |
3150 |
2100 |
The minimum pressure for tantalum and tantalum alloy tubes is listed in the above tables. The pressure increases with wall thickness and the percentage of tungsten (the higher tungsten, the higher the yield strength) and decreases with the outside diameter. Given a tube with a certain OD, the heat exchanger customer shall order tubes with thicker wall (or higher tungsten) if the customer would like tubes to hold higher pressure. (Normally we don't recommend customers to order tantalum with 10% tungsten (Ta10W), which increases the difficulty of production, to our knowledge.)
The numbers in Tables 1-3 are minimum values. Our actual numbers are typically at least 25% higher. The above data are calculated as follows:
P=2 S t / D
P: Minimum Hydrostatic Pressure, psi (or MPa)
S: Allowable Fiber Stress of 75% of the Minimum Yield Strength, psi (or MPa)
t: Average Wall Thickness of the Tube, inch (or mm), and
D: Outside Diameter of the Tube, inch (or mm)
Table 4 Minimum Yield Strength, psi (MPa) in ASTM B521 |
R05200 & R05400 Ta |
R05252 Ta2.5W |
R05255 Ta10W |
20,000 (138) |
28,000 (193) |
60,000 (414) |
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