NCI Engineering Tools
Engineering Tools
& Reference Calculators
Practical engineering calculators covering flow measurement, eductor sizing, mixing, noise abatement, filtration, and more — built around the product lines NCI represents.
All calculators provide estimates for preliminary engineering use. Contact NCI for final sizing and selection.
Engineering Reference Tables
Quick-reference data for common engineering calculations.
Pipe Schedule — Inside Diameters (inches)
| Nominal | Sch 40 | Sch 80 | Sch 160 |
|---|---|---|---|
| 1/2" | 0.622 | 0.546 | 0.466 |
| 3/4" | 0.824 | 0.742 | 0.614 |
| 1" | 1.049 | 0.957 | 0.815 |
| 1-1/4" | 1.380 | 1.278 | 1.160 |
| 1-1/2" | 1.610 | 1.500 | 1.338 |
| 2" | 2.067 | 1.939 | 1.689 |
| 2-1/2" | 2.469 | 2.323 | 2.125 |
| 3" | 3.068 | 2.900 | 2.624 |
| 4" | 4.026 | 3.826 | 3.438 |
| 6" | 6.065 | 5.761 | 5.187 |
| 8" | 7.981 | 7.625 | 6.813 |
| 10" | 10.020 | 9.562 | 8.500 |
| 12" | 11.938 | 11.374 | 10.126 |
Common Liquid SG & Viscosity (at ~60°F)
| Fluid | SG | Viscosity |
|---|---|---|
| Water (60°F) | 1.000 | 1.0 cSt |
| Water (212°F) | 0.958 | 0.29 cSt |
| Seawater | 1.025 | 1.1 cSt |
| Diesel Fuel | 0.850 | 2–5 cSt |
| Gasoline | 0.720 | 0.6 cSt |
| Crude Oil (light) | 0.820 | 5–20 cSt |
| Crude Oil (heavy) | 0.920 | 100–500 cSt |
| Lube Oil (ISO 32) | 0.860 | 32 cSt |
| Lube Oil (ISO 68) | 0.870 | 68 cSt |
| Hydraulic Oil (ISO 46) | 0.875 | 46 cSt |
| Ethylene Glycol (50%) | 1.070 | 4.0 cSt |
| Ammonia (liquid) | 0.682 | 0.25 cSt |
| Sulfuric Acid (98%) | 1.840 | 25 cSt |
| Caustic Soda (50%) | 1.530 | 45 cSt |
Common Gas SG (vs. Air = 1.0) & Molecular Weight
| Gas | SG (vs. Air) | Mol. Weight |
|---|---|---|
| Air | 1.000 | 28.97 |
| Natural Gas (typical) | 0.600 | 17.4 |
| Methane (CH₄) | 0.554 | 16.04 |
| Propane (C₃H₈) | 1.522 | 44.10 |
| Nitrogen (N₂) | 0.967 | 28.01 |
| Oxygen (O₂) | 1.105 | 32.00 |
| Carbon Dioxide (CO₂) | 1.519 | 44.01 |
| Hydrogen (H₂) | 0.069 | 2.016 |
| Steam (212°F) | 0.622 | 18.02 |
| Argon (Ar) | 1.380 | 39.95 |
| Ammonia (NH₃) | 0.597 | 17.03 |
| Chlorine (Cl₂) | 2.448 | 70.90 |
Engineering Rules of Thumb
Flow VelocityLiquids in pipe: 2–8 ft/s recommended; >10 ft/s risks erosion
Flow VelocitySteam in pipe: 50–150 ft/s; wet steam lower end
Flow VelocityGas in pipe: 20–60 ft/s typical; compressible effects above Mach 0.3
Flow MetersVariable-area meters: most accurate at Re > 10,000 (turbulent)
Flow MetersRotameter accuracy: typically ±2–5% of full scale
EductorsLiquid eductors: motive pressure must be 2–3× discharge pressure
EductorsTank mixing: 4–6 turnovers/hour for blending; 8–12 for suspension
SilencersOSHA PEL: 90 dB(A) at 8-hr TWA; target 85 dB(A) for safety margin
SilencersEvery 3 dB reduction = halving of sound power
FiltrationChange filter elements at 4× clean ΔP or per manufacturer spec
Steam TrapsSize steam traps at 3× calculated condensate load
Level GagesOverlap stacked gages by 1–2 inches at each connection
Need Precise Sizing or Selection?
These calculators are for preliminary engineering estimates. Our applications engineers are available to provide exact sizing, selection, and quotation for any NCI product line.
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