Tubing outer diameter hardness

It is most important that the tubing should be softer than the material of the fitting when selecting the suitable tubing for use in metal tube fitting.

Permissible pressure recommended by stainless steel

Stainless steel tubing conforms to ASTM A269 or A213 with an ultimate tensile strength of 75,000 psig (5,167 bar) at -28 to 37 °C as specified in ASME B31.3 and B31.1. For welded tube welds and drawn tubing, a factor is applied according to the degree of welding.  single welded tubing = working pressure * 0.80  double welded tubing = working pressure * 0.85

tube outer diameter (O.D) Wall thickness 0.010 0.012 0.014 0.016 0.020 0.028 0.035 0.049 0.065 0.083 0.095 0.109 0.120 working pressure (psig) 1/16" 5,600 6,800 8,100 9,400 12,000                 1/8"           8,500 10,900             3/16"           5,400 7,000 10,200           1/4"           4,000 5,100 7,500 10,200         5/16"             4,000 5,800 8,000         3/8"             3,300 4,800 6,500 7,500       1/2"             2,600 3,700 5,100 6,700       5/8"               2,900 4,000 5,200 6,000     3/4"               2,400 3,300 4,200 4,900 5,800   7/8"               2,000 2,800 3,600 4,200 4,800   1"                 2,400 3,100 3,600 4,200 4,700

[Table 1]

Recommended Order Information

High quality seamless or welded and drawn to ASTM A269 or A213 standards.  It is recommended to use for products with stainless steel hardness Rb80 or less.  It is recommended to use tubing without scratches on the surface to avoid problems with bending and expansion.

Recommended Allowable Pressure for Copper Seamless Tubing

Copper seamless tubing conforms to ASTM B68 and B79 with ultimate tensile strength of 30,000 psig (2,067 bar) at -28 to 37 °C as specified in ASME B31.3 and B31.1.

Tube outer diameter (O.D) Wall thickness 0.028 0.030 0.035 0.049 0.065 0.083 0.095 0.109 0.120 working pressure (psig) 1/8" 2,700 3,000 3,600             3/16" 1,800 1,900 2,300 3,400           1/4" 1,300 1,400 1,600 2,500 3,500         5/16"     1,300 1,900 2,700         3/8"     1,000 1,600 2,200         1/2"     800 1,100 1,600 2,100       5/8"       900 1,200 1,600 1,900     3/4"       700 1,000 1,300 1,500 1,800   7/8"       600 800 1,100 1,300 1,500   1"       500 700 900 1,100 1,300 1,500

[표2]

Recommended Order Information

The use of high-quality seamless copper tubing, ASTM B75 or equivalent, is recommended.

Permissible pressure at high temperature

To find the allowable pressure at high temperatures, multiply the values in [Table 1] and [Table 2] by the values in [Table 3] below.

For example, the size of Stainless steel 316 is 1/2" 0.49" to O.D." wall thickness and allowable pressure in an 800°F (427°C) environment 3750 psi X 0.79 = 2962.5 psig. °F ℃ ANSI 316SS COPPER 200 93 1 0.80 400 204 0.96 0.50 600 316 0.85 - 800 427 0.79 - 1000 538 0.76 - 1200 649 0.33 - [Table 3]