Plumbing Relative Roughness Calculator
Actual hydraulic relative roughnessε/d, same units no friction model; actual compatible definitions and matching units required, no causal efficacy/diagnosis or safety claim.
Description
Relative roughness compares a pipe's absolute roughness with its internal diameter.
Relative roughness compares a pipe's absolute roughness with its internal diameter.1
Both lengths must use the same unit. The calculation and input requirements are explained below.
When to use Plumbing Relative Roughness Calculator
Enter nonnegative absolute roughness and positive internal diameter in the same length unit.
How to use Plumbing Relative Roughness Calculator and how it works
- Prepare the measurements or independently established model inputs described below, with matching units and observation scope.
- Enter the required fields and run Plumbing Relative Roughness Calculator.
- Read the result fields using the formula, output units, signs and ordering explained below.
- Correct any rejected inputs and rerun; interpret the result within the stated model and its assumptions.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| actualAbsolutePipeRoughness | Actual Absolute Pipe Roughness. Use the units and matching context stated in the calculation below. | number | Required; nonnegative; finite; other constraints below |
| actualInnerDiameter | Actual Inner Diameter. Use the units and matching context stated in the calculation below. | number | Required; strictly positive; finite; other constraints below |
Enter nonnegative absolute roughness and positive internal diameter in the same length unit. Divide to return dimensionless relative roughness. No friction factor is selected.
relativeRoughness=absoluteRoughness/innerDiameter Apply the input ordering, units and branch conditions stated above.
| Output field | Meaning | Value type |
|---|---|---|
| result | Object containing the calculated or selected fields below. | object |
| result.value | Numeric result under the formula and output units explained above. | number |
{
"input": {
"actualAbsolutePipeRoughness": 2,
"actualInnerDiameter": 4
},
"output": {
"result": {
"value": 0.5
}
}
}Limitations and assumptions
The calculation uses the supplied observations and model inputs. It does not collect measurements, select a reference population or coefficient, or establish that the model applies to the actual case. The stated branch conditions and output units remain part of the result.
All fields require explicit values. Unexpected fields, wrong types, nonfinite numbers and sparse arrays are rejected. Alignment, bounds and supported-token rules are explained above; extremely large inputs or nonfinite results can also fail. Input errors differ from successful false comparisons, unavailable-domain flags and empty match lists.
Alternative or Complementary methods
Use Plumbing Valve Pressure Drop From Cv Calculator for a complementary operation: Liquid valve Cv relates flow and pressure drop under its applicable flow branch.
Use Plumbing Darcy Weisbach Head Loss Calculator for a complementary operation: Darcy–Weisbach head loss combines pipe length, bore, mean velocity and Darcy friction factor.
References
-
Plumbing Relative Roughness Calculator — tool.io
Similar or alternative tools
- Plumbing Valve Pressure Drop From Cv Calculator
Liquid valve Cv relates flow and pressure drop under its applicable flow branch.
- Plumbing Darcy Weisbach Head Loss Calculator
Darcy–Weisbach head loss combines pipe length, bore, mean velocity and Darcy friction factor.