How much pressure can stainless steel fittings hold?

SSP NPT Pipe End Pressure Ratings, ANSI/ASME B 31.3 - Table 6   316 Stainless Steel Brass Carbon Steel NPT/ISO Pipe Size Size Male Female Male Female Male Female     psig bar psig bar psig bar psig bar psig bar psig bar 1/16" 1 11,050 760 6,750 460 5,550 380 3,350 230 11,050 760 6,750 460 1/8" 2 10,050 690 6,550 450 5,050 350 3,250 220 10,050 690 6,550 450 1/4" 4 8,050 550 6,650 460 4,050 280 3,350 230 8,050 550 6,650 460 3/8" 6 7,850 540 5,350 370 3,950 270 2,650 180 7,850 540 5,350 370 1/2" 8 7,750 530 4,950 340 3,850 260 2,450 170 7,750 530 4,950 340 3/4" 12 7,350 510 4,650 320 3,650 250 2,350 160 7,350 510 4,650 320 1" 16 5,350 370 4,450 310 2,650 180 2,250 150 5,350 370 4,450 310 1-1/4" 20 6,000 410 5,000 350 3,000 200 2,500 170 6,000 410 5,000 350 1-1/2" 24 5,000 340 4,600 310 2,500 170 2,300 150 5,000 340 4,600 310 2" 32 3,900 270 3,900 270 1,900 300 1,900 130 3,900 270 3,900 270 Reference: bar = .0690 X psig To obtain ANSI/ASME B 31.1 values, multiply ANSI/ASME B 31.3 values by .94

Stainless Steel Tubing - Table 1
Maximum Allowable Working Pressure (PSIG) Tube O.D.   Wall Thickness of Tube (Inches) Size (Inches) .010 .012 .014 .016 .020 .028 .035 .049 .065 .083 .095 .109 .120 1/16 5600 6850 8150 9500 12100                 1/8           8550 11000     NOTE: For light gas service, use tubing with wall thickness outside of gray shaded area. 3/16           5450 7000 10300   1/4           4000 5100 7500 10300 5/16             4050 5850 8050         3/8             3300 4800 6550         1/2             2450 3500 4750 6250       5/8               2950 4000 5200 6050     3/4               2400 3300 4250 4950 5800   7/8               2050 2800 3600 4200 4850   1                 2400 3150 3650 4200 4700 1-1/4                   2450 2850 3300 3650 1-1/2                     2350 2700 3000 2                       2000 2200

Calculation Basis: Annealed, seamless 304 or 316 stainless steel tubing ASTM A-269 or equivalent. System temperatures between -20°F and 100°F with allowable stress of 20,000 psi. Ultimate tensile strength of 75,000 psi. Safety factor of 4. Reference: ANSI B 31.3 Code. (For more specific working pressure information regarding a particular tubing, consult with the actual manufacturer of the tubing.)

Note: For welded and drawn tubing, a derating factor must be utilized. For double welded tube, multiply the above pressure rating by .85; and for single welded tube by .80 (ANSI B 31, Table A-1B). Suggested Tube Ordering Information: Specify the outside diameter and wall thickness of annealed, seamless or welded and drawn 316 or 304 stainless steel tubing of ASTM A-269, A-249, A-213 or equivalent. Also specify high quality tubing to be free of scratches, and suited for bending with material hardness not to exceed Rb 90.

Generally, SSP fittings, adapters and components (fittings) are rated for pressures equal to the maximum allowable working pressures of the tubing, hose or pipe recommended for use with the fittings. However, it is important to note that many specially designed fittings, bored-through fittings and fittings having SAE/AN, O-Ring boss and SAE/MS integral ends may have lower pressure ratings than that of the tubing.

Copper Steel Tubing - Table 2
Maximum Allowable Working Pressure (PSIG) Tube O.D. Wall Thickness of Tube (Inches) Size (Inches) .028 .035 .049 .065 .083 .095 .109 .120 1/8 2700 3600             3/16 1700 2225 3450           1/4 1250 1600 2475 3475   NOTE: For light gas service, use tubing with wall thickness outside of gray screened area 5/16   1250 1900 2675   3/8   1050 1550 2150   1/2   750 1150 1550 2050       5/8     900 1200 1600 1850     3/4     700 1000 1275 1500 1775   7/8     600 850 1075 1250 1500   1     550 700 950 1100 1300 1400

Calculation Basis: Annealed (Temper 060), seamless copper tubing ASTM B-75 or equivalent. System temperatures between -20°F and 100°F with allowable stress of 6000 psi. Ultimate tensile strength of 30,000 psi. Safety factor of 5. Reference: ANSI B 31.3 Code. (For more specific working pressure information regarding a particular tubing, consult with the actual manufacturer of the tubing.)

Suggested Tube Ordering Information: Specify the outside diameter and wall thickness of annealed (Temper 060), seamless copper tubing of ASTM B-75, B-68, or equivalent specification. Also specify high quality tubing to be free of scratches, and suited for bending. Additionally acceptable: Annealed (Temper O) copper water tubing, Type K or Type L (ASTM B-88). No embossed markings allowed.

Monel® Alloy 400 Tubing - Table 4
Maximum Allowable Working Pressure (PSIG) Tube O.D. Wall Thickness of Tube (Inches) Size (Inches) .028 .035 .049 .065 .083 .095 .109 .120 1/8 8000 10450             1/4 3750 4800 7000 9800   NOTE: For light gas service, use tubing with wall thickness outside of gray screened area 3/8   3100 4450 6150   1/2   2300 3300 4450         3/4     2250 3050 4000 4600     1       2250 2900 3400 3900 4350

Monel 400 is a trademark of INCO Alloys International Incorporated. Calculation Basis: Annealed, seamless Monel Alloy 400 tubing ASTM B-165 or equivalent. System temperatures between -20°F and 100°F with allowable stress of 18,700 psi. Ultimate tensile strength of 70,000 psi. Safety factor of 4. Table values are per the ANSI/ASME B 31.3 Code for temperatures from -325°F to only 100°F. Monel derates fast at elevated temperatures. (For more specific working pressure information regarding a particular tubing, consult with the actual manufacturer of the tubing.) Suggested Tube Ordering Information: Specify the outside diameter and wall thickness of annealed, seamless Monel Alloy 400 tubing of ASTM B-165 or equivalent specification. Also specify high quality tubing to be free of scratches, and suited for bending with material hardness not to exceed Rb 75.