Threaded Elbow
Threaded Elbow (90° & 45°) Pipe Fittings
Threaded Elbows are pipe fittings that alter the direction of flow in a piping system.. Available primarily in 90-degree and 45-degree angles, these elbows are connected to pipes via female threads, ensuring quick and leak-proof assembly without welding.
| Feature | 90° Threaded Elbow | 45° Threaded Elbow |
|---|---|---|
| Purpose | Changes the direction of flow in a piping system by 90 degrees. | Changes the direction of flow in a piping system by 45 degrees. |
| Standards | ASME B16.11, BS 3799, ISO 4144, ANSI/ASME B1.20.1 (NPT), BSPT, BSPP | ASME B16.11, BS 3799, ISO 4144, ANSI/ASME B1.20.1 (NPT), BSPT, BSPP |
| Size Range | 1/8″ to 4″ (NPS) | 1/8″ to 4″ (NPS) |
| Pressure Classes | Class 2000, 3000, 6000, 9000 | Class 2000, 3000, 6000, 9000 |
| Thread Types | NPT, BSPT, BSPP, PT, PF; Female/Female, Male/Female (Street Elbow) | NPT, BSPT, BSPP, PT, PF; Female/Female, Male/Female (Street Elbow) |
| Radius Types | Short Radius (SR): Centre-to-Face = 1.0x diameter; Long Radius (LR): 1.5x diameter | Short Radius (SR): Centre-to-Face = 1.0x diameter; Long Radius (LR): 1.5x diameter |
| Materials | – Stainless Steel: ASTM A182 F304, F316, F316L, F321, F347, F904L – Carbon Steel: ASTM A105, A350 LF2 – Alloy Steel: ASTM A182 F5, F9, F11, F22, F91 – Duplex/Super Duplex: ASTM A182 F51, F53, F55 – Copper Alloys: ASTM SB 111 (C10100, C10200, etc.) – Nickel Alloys: Inconel, Monel, Hastelloy – Others: Brass, Malleable Iron, Cast Iron | Same as 90° Threaded Elbow |
| Applications | – Plumbing, HVAC, chemical processing, oil & gas, petrochemical, water supply – Suitable for small pipe diameters (NPS 2 or smaller for high-pressure systems) – Used in tight spaces (SR) or critical flow systems (LR) | – Low-pressure gravity-fed systems, air-conditioning, water supply, chemical pipelines – Preferred in applications requiring minimal turbulence and deposition of solids (e.g., DWV systems, sewage, central vacuum systems) |
| Connection Types | Threaded (Female/Female, Male/Female for Street Elbows), Straight or Reducing | Threaded (Female/Female, Male/Female for Street Elbows), Straight or Reducing |
| Key Features | – Provides smooth transition, reducing turbulence and pressure loss – Easy to install and disassemble for repairs – Corrosion-resistant materials (e.g., SS, brass) for harsh environments – Street elbows connect male and female threads | – Gentler bend reduces friction and pressure drop compared to 90° elbows – Suitable for low-turbulence systems – Corrosion-resistant materials available – Street elbows for mixed thread connections |
| Common Issues | – Pressure losses due to friction, impact, and re-acceleration – Potential wear with abrasive products – Sensitive products may cause contamination or degradation | – Similar to 90° elbows but less pronounced due to gentler angle – Material selection critical for abrasive or corrosive media |
| Sealing Types | NPT (60° thread angle, tapered), BSPP (parallel threads), BSPT (tapered) | NPT (60° thread angle, tapered), BSPP (parallel threads), BSPT (tapered) |
| Typical Industries | Oil & gas, petrochemical, chemical processing, plumbing, HVAC, marine | Water supply, sewage, chemical processing, agriculture, solar-energy piping |
Threaded Elbow Dimensions
Class 2000
| NPS | Min Thread Length | Outside Dia | Min WT | Center to End | ||
| B | J | D | G | 90° A | 45° C | |
| 1/2 | 10.9 | 13.6 | 33 | 3.18 | 28 | 22 |
| 3/4 | 12.7 | 13.9 | 38 | 3.18 | 33 | 25 |
| 1 | 14.7 | 17.3 | 46 | 3.68 | 38 | 28 |
| 1.1/4 | 17 | 18 | 56 | 3.89 | 44 | 33 |
| 1.1/2 | 17.8 | 18.4 | 62 | 4.01 | 51 | 35 |
| 2 | 19 | 19.2 | 75 | 4.27 | 60 | 43 |
| 2.1/2 | 23.6 | 28.9 | 92 | 5.61 | 76 | 52 |
| 3 | 25.9 | 30.5 | 109 | 5.99 | 86 | 64 |
| 4 | 27.7 | 33 | 146 | 6.55 | 106 | 79 |
Class 3000
| NPS | Min Thread Length | Outside Dia | Min WT | Center to End | ||
| B | J | D | G | 90° A | 45° C | |
| 1/2 | 10.9 | 13.6 | 38 | 4.09 | 33 | 25 |
| 3/4 | 12.7 | 13.9 | 46 | 4.32 | 38 | 28 |
| 1 | 14.7 | 17.3 | 56 | 4.98 | 44 | 33 |
| 1.1/4 | 17 | 18 | 62 | 5.28 | 51 | 35 |
| 1.1/2 | 17.8 | 18.4 | 75 | 5.56 | 60 | 43 |
| 2 | 19 | 19.2 | 84 | 7.14 | 64 | 44 |
| 2.1/2 | 23.6 | 28.9 | 102 | 7.65 | 83 | 52 |
| 3 | 25.9 | 30.5 | 121 | 8.84 | 95 | 64 |
| 4 | 27.7 | 33 | 152 | 11.18 | 114 | 79 |
Class 6000
| NPS | Min Thread Length | Outside Dia | Min WT | Center to End | ||
| B | J | D | G | 90° A | 45° C | |
| 1/2 | 10.9 | 13.6 | 46 | 8.15 | 38 | 28 |
| 3/4 | 12.7 | 13.9 | 56 | 8.53 | 44 | 33 |
| 1 | 14.7 | 17.3 | 62 | 9.93 | 51 | 35 |
| 1.1/4 | 17 | 18 | 75 | 10.59 | 60 | 43 |
| 1.1/2 | 17.8 | 18.4 | 84 | 11.07 | 64 | 44 |
| 2 | 19 | 19.2 | 102 | 12.09 | 83 | 52 |
| 2.1/2 | 23.6 | 28.9 | 121 | 15.29 | 95 | 64 |
| 3 | 25.9 | 30.5 | 146 | 16.64 | 106 | 79 |
| 4 | 27.7 | 33 | 152 | 18.67 | 114 | 79 |
Types of Threaded Elbows
90° Threaded Elbow
Changes the direction of flow at a right angle.
Common in water, oil, gas, and chemical pipelines.
Available in short radius and long radius types.
45° Threaded Elbow
Offers a smoother directional change at a 45° angle.
Reduces flow resistance compared to 90° elbows.
Ideal for tight spaces requiring gentle flow redirection.
Key Features
Connection: Female NPT/BSP threads
Material: Stainless Steel, Carbon Steel, Alloy Steel, Brass, etc.
Pressure Ratings: Class 2000 / 3000 / 6000
Standards: ASME B16.11, MSS SP-79, BS 3799
Size Range: 1/8” to 4” (DN6 to DN100)
Applications
Plumbing and piping systems
Oil and gas distribution
Fire protection systems
Petrochemical and chemical processing