NPS 20 Schedule 5 Pipe
20.000 in (508.0 mm) outside diameter on a 0.188 in (4.8 mm) wall, giving a 19.624 in (498.4 mm) bore and 39.78 lb/ft (59.20 kg/m) empty. ASME B36.10M.
- Nominal size
- NPS 20 (DN 500)
- Schedule
- Schedule 5
- Outside diameter
- 20.000 in (508.0 mm)
- Wall thickness
- 0.188 in (4.8 mm)
- Inside diameter
- 19.624 in (498.4 mm)
- Weight, empty
- 39.78 lb/ft (59.20 kg/m)
- Weight, water filled
- 170.90 lb/ft (254.33 kg/m)
- Flow area
- 302.458 in² (195134 mm²)
No other designation in NPS 20 shares this wall thickness, so Schedule 5 is unambiguous in this size.
Every schedule in NPS 20
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 | 0.1884.78 mm | 19.624498.45 mm | 39.7859.20 kg/m | 15.712 |
| Sch 10 | 0.2185.54 mm | 19.564496.93 mm | 46.0668.54 kg/m | 15.616 |
| Sch 20 | 0.3759.52 mm | 19.250488.95 mm | 78.60116.97 kg/m | 15.119 |
| Sch 30 | 0.50012.70 mm | 19.000482.60 mm | 104.13154.97 kg/m | 14.729 |
| Sch 40 | 0.59415.09 mm | 18.812477.82 mm | 123.11183.21 kg/m | 14.439 |
| STD | 0.3759.52 mm | 19.250488.95 mm | 78.60116.97 kg/m | 15.119 |
| Sch 60 | 0.81220.62 mm | 18.376466.75 mm | 166.40247.64 kg/m | 13.777 |
| Sch 80 | 1.03126.19 mm | 17.938455.63 mm | 208.87310.84 kg/m | 13.128 |
| XS | 0.50012.70 mm | 19.000482.60 mm | 104.13154.97 kg/m | 14.729 |
| Sch 100 | 1.28132.54 mm | 17.438442.93 mm | 256.10381.12 kg/m | 12.407 |
| Sch 120 | 1.50038.10 mm | 17.000431.80 mm | 296.38441.05 kg/m | 11.791 |
| Sch 140 | 1.75044.45 mm | 16.500419.10 mm | 341.10507.61 kg/m | 11.108 |
| Sch 160 | 1.96950.01 mm | 16.062407.97 mm | 379.18564.28 kg/m | 10.526 |
Weight is plain-end carbon steel, w = 10.6802 × t × (OD − t) lb/ft.
Flanges for NPS 20 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 19.624 in (498.4 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 | 27.50698.50 mm | 1.6942.93 mm | 25.00635.00 mm | 20 × 1 1/8 in |
| Class 300 | 30.50774.70 mm | 2.5063.50 mm | 27.00685.80 mm | 24 × 1 1/4 in |
| Class 400 | 30.50774.70 mm | 2.7569.85 mm | 27.00685.80 mm | 24 × 1 1/2 in |
| Class 600 | 32.00812.80 mm | 3.5088.90 mm | 28.50723.90 mm | 24 × 1 5/8 in |
| Class 900 | 33.75857.25 mm | 4.25107.95 mm | 29.50749.30 mm | 20 × 2 in |
| Class 1500 | 38.75984.25 mm | 7.00177.80 mm | 32.75831.85 mm | 16 × 3 in |
Fittings for NPS 20 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 20 |
|---|---|---|
| 90° Long Radius Elbow | Centre-to-end A | 30.00762.00 mm |
| 90° Short Radius Elbow | Centre-to-end A | 20.00508.00 mm |
| 45° Long Radius Elbow | Centre-to-end B | 12.50317.50 mm |
| Straight Tee | Centre-to-end C and M | 15.00381.00 mm |
| Reducing Tee | Run centre-to-end C | 15.00381.00 mm |
| Concentric Reducer | End-to-end H | 20.00508.00 mm |
| Eccentric Reducer | End-to-end H | 20.00508.00 mm |
| Cap | Length E | 9.00228.60 mm |
Common questions
What is the inside diameter of NPS 20 schedule 5 pipe?
19.624 in (498.4 mm). The outside diameter is fixed at 20.000 in (508.0 mm) by ASME B36.10M, and the 0.188 in (4.8 mm) wall takes 0.376 in off it — 0.188 in from each side — leaving that bore.
How much does NPS 20 schedule 5 pipe weigh?
39.78 lb/ft (59.20 kg/m) empty, as plain-end carbon steel. Full of water it comes to 170.90 lb/ft (254.33 kg/m), because the bore holds 15.712 US gallons per foot. One short ton of this pipe is about 50 ft.
Does NPS 20 schedule 5 pipe use special flanges or fittings?
No. Flanges and buttweld fittings are dimensioned from NPS, so NPS 20 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 19.624 in (498.4 mm) to match.