NPS 1 1/4 Schedule 5 Pipe
1.660 in (42.2 mm) outside diameter on a 0.065 in (1.7 mm) wall, giving a 1.530 in (38.9 mm) bore and 1.11 lb/ft (1.65 kg/m) empty. ASME B36.10M.
- Nominal size
- NPS 1 1/4 (DN 32)
- Schedule
- Schedule 5
- Outside diameter
- 1.660 in (42.2 mm)
- Wall thickness
- 0.065 in (1.7 mm)
- Inside diameter
- 1.530 in (38.9 mm)
- Weight, empty
- 1.11 lb/ft (1.65 kg/m)
- Weight, water filled
- 1.90 lb/ft (2.83 kg/m)
- Flow area
- 1.839 in² (1186 mm²)
No other designation in NPS 1 1/4 shares this wall thickness, so Schedule 5 is unambiguous in this size.
Every schedule in NPS 1 1/4
Dimensions are given in inches, with the millimetre equivalent beneath in grey.
| Schedule | Wall thickness | Inside diameter | Weight, empty | Water (US gal/ft) |
|---|---|---|---|---|
| Sch 5 this page | 0.0651.65 mm | 1.53038.86 mm | 1.111.65 kg/m | 0.096 |
| Sch 10 | 0.1092.77 mm | 1.44236.63 mm | 1.812.69 kg/m | 0.085 |
| Sch 40 | 0.1403.56 mm | 1.38035.05 mm | 2.273.38 kg/m | 0.078 |
| STD | 0.1403.56 mm | 1.38035.05 mm | 2.273.38 kg/m | 0.078 |
| Sch 80 | 0.1914.85 mm | 1.27832.46 mm | 3.004.46 kg/m | 0.067 |
| XS | 0.1914.85 mm | 1.27832.46 mm | 3.004.46 kg/m | 0.067 |
| Sch 160 | 0.2506.35 mm | 1.16029.46 mm | 3.765.60 kg/m | 0.055 |
| XXS | 0.3829.70 mm | 0.89622.76 mm | 5.217.76 kg/m | 0.033 |
Weight is plain-end carbon steel, w = 10.6802 × t × (OD − t) lb/ft.
Flanges for NPS 1 1/4 pipe
Flange dimensions are set by NPS and pressure class, not by schedule, so every flange below fits this pipe. The exception is the weld neck: its bore is machined to the pipe it is welded to, which for Schedule 5 means 1.530 in (38.9 mm). Order the flange to the schedule or the bores will not line up at the weld.
| Class | Flange OD | Thickness | Bolt circle | Bolting |
|---|---|---|---|---|
| Class 150 | 4.62117.35 mm | 0.6215.75 mm | 3.5088.90 mm | 4 × 1/2 in |
| Class 300 | 5.25133.35 mm | 0.7519.05 mm | 3.8898.55 mm | 4 × 5/8 in |
| Class 400 | 5.25133.35 mm | 0.8120.57 mm | 3.8898.55 mm | 4 × 5/8 in |
| Class 600 | 5.25133.35 mm | 0.8120.57 mm | 3.8898.55 mm | 4 × 5/8 in |
| Class 900 | 6.25158.75 mm | 1.1228.45 mm | 4.38111.25 mm | 4 × 7/8 in |
| Class 1500 | 6.25158.75 mm | 1.1228.45 mm | 4.38111.25 mm | 4 × 7/8 in |
| Class 2500 | 7.25184.15 mm | 1.5038.10 mm | 5.12130.05 mm | 4 × 1 in |
Fittings for NPS 1 1/4 pipe
ASME B16.9 dimensions come from NPS alone, so these figures hold for Schedule 5 exactly as they do for every other schedule in the size. Only the wall thickness has to be ordered to match.
| Fitting | Dimension | NPS 1 1/4 |
|---|---|---|
| 90° Long Radius Elbow | Centre-to-end A | 1.8847.75 mm |
| 90° Short Radius Elbow | Centre-to-end A | 1.2531.75 mm |
| 45° Long Radius Elbow | Centre-to-end B | 1.0025.40 mm |
| Straight Tee | Centre-to-end C and M | 1.8847.75 mm |
| Reducing Tee | Run centre-to-end C | 1.8847.75 mm |
| Concentric Reducer | End-to-end H | 2.0050.80 mm |
| Eccentric Reducer | End-to-end H | 2.0050.80 mm |
| Cap | Length E | 1.5038.10 mm |
Common questions
What is the inside diameter of NPS 1 1/4 schedule 5 pipe?
1.530 in (38.9 mm). The outside diameter is fixed at 1.660 in (42.2 mm) by ASME B36.10M, and the 0.065 in (1.7 mm) wall takes 0.130 in off it — 0.065 in from each side — leaving that bore.
How much does NPS 1 1/4 schedule 5 pipe weigh?
1.11 lb/ft (1.65 kg/m) empty, as plain-end carbon steel. Full of water it comes to 1.90 lb/ft (2.83 kg/m), because the bore holds 0.096 US gallons per foot. One short ton of this pipe is about 1806 ft.
Does NPS 1 1/4 schedule 5 pipe use special flanges or fittings?
No. Flanges and buttweld fittings are dimensioned from NPS, so NPS 1 1/4 hardware fits this pipe in any schedule. The one thing that does follow the schedule is the bore of a weld neck flange or a fitting end prep, which has to be 1.530 in (38.9 mm) to match.