Tube O.D.Size (Inches)  Wall Thickness of Tube (inches)             
 .010 .012 .014 .016 .020 .028 .035 .049 .065 .083 .095 .109 .120 .134 0156 .188
Working Pressure, psig
1/16 5600 6800 8100 9400 12100                      
1/8           8500 10900                  
3/16           5400 7000 10200                
1/4           4000 5100 7500 10200              
5/16             4000 5800 8000              
3/8             3300 4800 6500              
1/2             2600 3700 5100 6700            
5/8               2900 4000 5200 6000          
3/4               2400 3300 4200 4900 5800        
7/8               2000 2800 3600 4200 4800        
1                 2400 3100 3600 4200 4700      
1-1/4                   2400 2800 3300 3600 4100 4900  
1-1/2                     2300 2700 3000 3400 4000 4900
2                       2000 2200 2500 2900 3600

Stress Factors For Determining Tubing Pressure Ratings at Elevated Temperatures

Temperature Stainless Steel CarbonSteelCopperMonel®400
°F °C304SS316SS   
100 381.001.001.001.001.00
200931.001.00.96.80.88
3001491.001.00.90.78.82
400200.94.97.86.50.79
500260.88.90.82n/a0.79
600316.82.85.77n/a.79
700371.80.82.73n/a.79
800427.76*.80*.59n/a.76
900482.73*.78*.41n/a.43
1000538.69*.73*.16n/an/a
1200649.30*.37n/an/an/a

* The precipitation of chromium carbides potentially resulting in intergranular corrosion may occur when exposed to operating temperatures above 800°F. Consult the factory for further information.

Instructions

To determine maximum allowable working pressures for tubing at elevated temperatures, multiply the applicable tube’s maximum allowable working pressure from Tubing Allowable Work Pressure Table by the corresponding temperature stress factor from Pressure-Temperature Derating Table above.

Duolok tube fittings function reliably in applications ranging from cryogenic temperatures to high temperature bake out with the tube fitting material as the limiting factor. It is important to note that elevated temperatures will reduce the maximum working pressure capability of the tubing system. (For more information regarding the effects of temperature on tubing pressure ratings, refer to Table 5 regarding temperature stress factors in SSP’s Selection Guide for Instrumentation Fittings and Tubing).