Tube O.D.Size (Inches)  Wall Thickness of Tube (inches)             
 .010 .012 .014 .016 .020 .028 .035 .049 .065 .083 .095 .109 .120 .134 .156 .188
Stainless Steel tubing - maximum allowable 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
Temperature°F Temperature°CStainless Steel 304SSStainless Steel 316SSCarbonSteel Copper Monel®400 
Temperature100 Temperature38Stainless Steel 1.00Stainless Steel 1.00CarbonSteel1.00Copper1.00Monel®4001.00
Temperature200Temperature93Stainless Steel 1.00Stainless Steel 1.00CarbonSteel.96Copper.80Monel®400.88
Temperature300Temperature149Stainless Steel 1.00Stainless Steel 1.00CarbonSteel.90Copper.78Monel®400.82
Temperature400Temperature200Stainless Steel .94Stainless Steel .97CarbonSteel.86Copper.50Monel®400.79
Temperature500Temperature260Stainless Steel .88Stainless Steel .90CarbonSteel.82Coppern/aMonel®4000.79
Temperature600Temperature316Stainless Steel .82Stainless Steel .85CarbonSteel.77Coppern/aMonel®400.79
Temperature700Temperature371Stainless Steel .80Stainless Steel .82CarbonSteel.73Coppern/aMonel®400.79
Temperature800Temperature427Stainless Steel .76*Stainless Steel .80*CarbonSteel.59Coppern/aMonel®400.76
Temperature900Temperature482Stainless Steel .73*Stainless Steel .78*CarbonSteel.41Coppern/aMonel®400.43
Temperature1000Temperature538Stainless Steel .69*Stainless Steel .73*CarbonSteel.16Coppern/aMonel®400n/a
Temperature1200Temperature649Stainless Steel .30*Stainless Steel .37CarbonSteeln/aCoppern/aMonel®400n/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).