Installation

EQOfluids aluminium compressed-air pipe dimensions

EQOfluids aluminium tube comes in two pressure classes, at the same outside diameter but with a different wall (and therefore bore):

  • PN16 — working pressure 232 psi (16 bar): the standard class for plant compressed air.
  • PN70 — working pressure 1015 psi (70 bar): the high-pressure class.

Bars are sold in 4 m (13 ft) and 6 m (20 ft) depending on diameter. The inside diameter (bore) — the one that sets air velocity and pressure drop — is not printed on the chart; compute it as ID = D − 2 × S. It is given below (Inside diameter column).

PN16 pipe — 232 psi (16 bar)

Outside dia. (D)Inside dia.*Wall (S)WeightLengths
20 mm (0.79 in)18.0 mm (0.71 in)1.00 mm0.19 kg/m (0.13 lb/ft)4 m · 6 m
25 mm (0.98 in)22.8 mm (0.90 in)1.10 mm0.24 kg/m (0.16 lb/ft)4 m · 6 m
32 mm (1.26 in)29.6 mm (1.17 in)1.20 mm0.33 kg/m (0.22 lb/ft)4 m · 6 m
40 mm (1.57 in)37.4 mm (1.47 in)1.30 mm0.43 kg/m (0.29 lb/ft)4 m · 6 m
50 mm (1.97 in)47.0 mm (1.85 in)1.50 mm0.58 kg/m (0.39 lb/ft)4 m · 6 m
63 mm (2.48 in)59.4 mm (2.34 in)1.80 mm1.02 kg/m (0.69 lb/ft)4 m · 6 m
90 mm (3.54 in)85.2 mm (3.35 in)2.40 mm1.09 kg/m †6 m
110 mm (4.33 in)104.0 mm (4.09 in)3.00 mm2.86 kg/m (1.92 lb/ft)6 m
140 mm (5.51 in)132.4 mm (5.21 in)3.80 mm4.57 kg/m (3.07 lb/ft)6 m
160 mm (6.30 in)151.4 mm (5.96 in)4.30 mm5.89 kg/m (3.96 lb/ft)6 m

PN70 pipe — 1015 psi (70 bar)

Outside dia. (D)Inside dia.*Wall (S)WeightLengths
20 mm (0.79 in)16.0 mm (0.63 in)2.00 mm0.31 kg/m (0.21 lb/ft)4 m · 6 m
25 mm (0.98 in)20.0 mm (0.79 in)2.50 mm0.48 kg/m (0.32 lb/ft)4 m · 6 m
32 mm (1.26 in)26.0 mm (1.02 in)3.00 mm0.74 kg/m (0.50 lb/ft)4 m
40 mm (1.57 in)32.0 mm (1.26 in)4.00 mm1.23 kg/m (0.83 lb/ft)4 m
50 mm (1.97 in)40.0 mm (1.57 in)5.00 mm1.91 kg/m (1.28 lb/ft)4 m
63 mm (2.48 in)51.0 mm (2.01 in)6.00 mm2.90 kg/m (1.95 lb/ft)4 m

* Computed inside diameter (D − 2 × S), not printed on the EQOfluids chart. This is the useful bore for air velocity and pressure drop. † Weight per the EQOfluids specification (Ø 90: 1.09 kg/m), reproduced as-is from their official dimension chart.

Why the bore matters

For a given flow (SCFM), the smaller the bore, the higher the air velocity and the larger the pressure drop (Bernoulli’s principle — CAGI, handbook ch. 4). That is why sizing is done on the inside diameter, and why, at equal outside diameter, a PN70 tube (thicker wall, smaller bore) creates more pressure drop than a PN16. For the full method, see Sizing compressed-air piping.

Ordering references

EQOfluids part numbers encode the model (pressure class) in the prefix, then the diameter and the bar length (suffix .104 = 4 m bar, .106 = 6 m bar). For the exact reference of a size, see the network accessories catalogue.

With the Onyx M3 tools

  • Network estimator — picks the EQOfluids aluminium diameter from the real flow and builds the bill of materials (pipe, takeoffs, outlets, supports).
  • Calculator — Pipe sizing — compares diameters by pressure drop and by velocity.

See also Cutting and assembling the pipe and Supports and fixing the pipework.

References

  • EQOfluidsPipe Dimension Chart (official tube dimension chart, PN16 and PN70 classes): https://www.eqofluids.com/pipe-dimension-chart/
  • CAGI — Compressed Air & Gas Handbook (7th ed., 2021), Chapter 4 — velocity and pressure drop depend on the inside diameter (Bernoulli’s principle)

Frequently asked questions

What is the difference between EQOfluids PN16 and PN70 pipe?

It is the maximum working pressure. PN16 is rated for 16 bar (232 psi) — the standard class for plant compressed air. PN70 is rated for 70 bar (1015 psi) — the high-pressure class. For the same outside diameter, PN70 has a thicker wall, so a smaller inside diameter (bore).

Is the "D" on the EQOfluids chart the inside or outside diameter?

It is the OUTSIDE diameter of the tube, in mm (20, 25, 32, 40, 50, 63, 90, 110, 140, 160). The inside diameter — the one that sets air velocity and pressure drop — is found by subtracting twice the wall thickness: ID = D − 2 × S.

In what lengths are EQOfluids bars sold?

In 4 m (13 ft) and 6 m (20 ft) bars depending on diameter. The listed weight is per metre (kg/m), so it does not depend on bar length.

Which diameter should I pick for my network?

Diameter is chosen on flow (SCFM), length and allowable pressure drop — not on the compressor diameter. See Sizing compressed-air piping, or let the network estimator pick the EQOfluids diameter and build the bill of materials.

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