Steel Tubes - Working Pressures vs. Size
Normal maximum working pressures for steel tubes - in psi and kPa.
The working pressures below are conservative estimates. Be aware that domestic rules may give lower limits.
For full table with Steam/Air Welded Connections - rotate the screen!
Nominal bore | Water | Steam / Air, screwed connections | Steam / Air, welded connections | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Light | Medium | Heavy | Medium | Heavy | Medium | Heavy | |||||||||
inches | mm | psi | kPa | psi | kPa | psi | kPa | psi | kPa | psi | kPa | psi | kPa | psi | kPa |
1/4 | 8 | 150 | 1000 | 300 | 2000 | 350 | 2400 | 150 | 1000 | 175 | 1200 | 250 | 1750 | 300 | 2000 |
3/8 | 10 | 150 | 1000 | 300 | 2000 | 350 | 2400 | 150 | 1000 | 175 | 1200 | 250 | 1750 | 300 | 2000 |
1/2 | 15 | 150 | 1000 | 300 | 2000 | 350 | 2400 | 150 | 1000 | 175 | 1200 | 250 | 1750 | 300 | 2000 |
3/4 | 20 | 150 | 1000 | 300 | 2000 | 350 | 2400 | 150 | 1000 | 175 | 1200 | 250 | 1750 | 300 | 2000 |
1 | 25 | 150 | 1000 | 300 | 2000 | 350 | 2400 | 150 | 1000 | 175 | 1200 | 250 | 1750 | 300 | 2000 |
1 1/4 | 32 | 125 | 850 | 250 | 1750 | 300 | 2000 | 125 | 850 | 150 | 1000 | 200 | 1400 | 300 | 2000 |
1 1/2 | 40 | 125 | 850 | 250 | 1750 | 300 | 2000 | 125 | 850 | 150 | 1000 | 200 | 1400 | 300 | 2000 |
2 | 50 | 100 | 700 | 200 | 1400 | 250 | 1750 | 100 | 700 | 125 | 850 | 200 | 1400 | 300 | 2000 |
2 1/2 | 65 | 100 | 700 | 200 | 1400 | 250 | 1750 | 100 | 700 | 125 | 850 | 200 | 1400 | 300 | 2000 |
3 | 80 | 100 | 700 | 200 | 1400 | 250 | 1750 | 100 | 700 | 125 | 850 | 150 | 1000 | 200 | 1400 |
4 | 100 | 80 | 550 | 150 | 1000 | 200 | 1400 | 80 | 550 | 100 | 700 | 150 | 1000 | 200 | 1400 |
5 | 125 | 150 | 1000 | 200 | 1400 | 80 | 550 | 100 | 700 | 150 | 1000 | 200 | 1400 | ||
6 | 150 | 125 | 850 | 150 | 1400 | 60 | 400 | 80 | 550 | 125 | 850 | 75 | 1200 |
- 1 psi = 1 lb/in2
- 1 kPa = 1 kN/m2