Flowline Components
D SEAL TUBE FITTINGS: A VERSATILE FITTING FOR MANY APPLICATIONS

MAXIMUM WORKING PRESSURES (PIPE THREADS ENDS)

Pressure ratings for fittings that have both tube fittings and pipe thread ends are determined by the end connection with the lowest pressure rating. The pipe end pressure ratings chart lists pressure ratings for male and female pipe thread ends.
NPT/ISO Pipe Size (in)
316 Stainless steel and carbon steel
Brass
Male
Female
Male
Female
psi
bar
psi
bar
psi
bar
psi
bar
1/16" 11000 760 6700 460 5500 380 3300 230
1/8" 10000 690 6500 440 5000 340 3200 220
1/4" 8000 550 6600 450 4000 270 3300 220
3/8" 7800 540 5300 360 3900 270 2600 180
1/2" 7700 530 4900 330 3800 260 2400 160
3/4" 7300 500 4600 320 3600 250 2300 160
1" 5300 370 4400 300 2600 180 2200 150
1.1/4" 6000 410 5000 350 3000 200 2500 170
1.1/2" 5000 340 4600 310 2500 170 2300 150
Calculations based on ASME B31.3 code for Process Piping.
To determine working pressure ratings in accordance with ASME B31.1 Power Piping for 316 stainless steel, multiply psi by 0.94; for carbon steel, multiply psi by 0.75. Brass ratings remain the same.


SAE PRESSURE RATINGS

Pressure ratings are from SAE J1926/3.
SAE Thread Size
316 Stainless steel and carbon steel
Nonpositionable
Positionable
psi
bar
psi
bar
7/16-20 4568 315 4568 315
9/16-18 4568 315 3626 250
3/4-16 4568 315 3626 250
7/8-14 3626 250 2900 200
1.1/16-12 3626 250 2900 200
1.5/16-12 2900 200 2320 160



DERATING FACTORS FOR ELEVATED TEMPERATURE APPLICATIONS



Pressure rating procedure
1. For applications involving service at elevated temperatures, the pressure rating must be multiplied by an appropriate temperature derating factor obtained from the temperature derating chart above.

2. Carbon steel tube fittings not normally recommended above 600°F/315°C.

3. Type 316 stainless steel tube fittings not normally recommended above 800°F/426°C.

4. Brass tube fittings not normally recommended above 425°F/218°C.

5. These working pressures are not necessarily valid for system components. Prudent system design requires that all other system components be evaluated for their specific proper pressure capabilities.