EZ STEEL
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a) ASME/ANSI Standards (USA & International)
b) BSP Standards (Europe/Asia)
c) JIS (Japanese Standard)
| Fitting Type | Common Size Range (NPS) | Max. Typical Size |
|---|---|---|
| Threaded Elbow | 1/8" to 12" | 12" (limited beyond) |
| Threaded Tee | 1/8" to 12" | 12" |
| Threaded Coupling | 1/8" to 12" | 12" |
| Threaded Reducer | 1/8" to 12" | 12" |
| Threaded Cap | 1/8" to 12" | 12" |
| Threaded Union | 1/8" to 4" | 4" (larger = impractical) |
Notes:
| Thread Type | Description | Sealing Method |
|---|---|---|
| NPT (Tapered) | Tapered thread (1.79° angle) | Thread sealant (Teflon tape, pipe dope) |
| BSPT (Tapered) | British Standard (1.47° angle) | Thread sealant |
| BSPP (Parallel) | Straight thread (G-series) | O-ring/gasket required |
| SAE Straight | Used in hydraulics | Metal-to-metal sealing |
Key Differences: NPT vs. BSPT: NPT has a steeper taper; they are not interchangeable. BSPP (G-thread) requires a washer/O-ring (common in hydraulics).
a) Installation Steps
b) Disassembly
| Feature | Threaded | Socket-Weld (SW) | Butt-Weld (BW) |
|---|---|---|---|
| Connection Type | Screwed (NPT/BSP) | Pipe inserted & fillet-welded | Pipe butted & fully welded |
| Pressure Rating | Low-Medium (≤3000 PSI) | High (Up to 9000) | Very High (Unlimited) |
| Leak Resistance | Moderate (sealant needed) | High (welded) | Best (full penetration) |
| Size Range | 1/8" – 12" | 1/8" – 4" | 1/2" – 48"+ |
| Installation Speed | Fastest (no welding) | Moderate (welding) | Slowest (precision welding) |
| Disassembly | Easy (reusable) | Difficult (cutting) | Permanent (cutting) |
| Cost | Lowest | Medium | Highest |
✔ Ideal Applications:
✖ Avoid For:
Conclusion: Threaded fittings are ideal for low-cost, easy-installation systems where welding is impractical. NPT (USA) and BSP (Europe/Asia) are the dominant standards. Best for water lines, compressed air, and maintenance-heavy systems.
