Plumbing Control Valve Authority Calculator
Audit actual matched design-flow valve/circuit pressure budget as authority, not K or cavitation index and no universal controllability threshold.
Description
Valve authority compares a valve’s pressure drop with its total circuit drop at the same design flow.
Valve authority compares a valve’s pressure drop with its total circuit drop at the same design flow. It is dimensionless.1
The returned values include Observed valve authority fractions. The How section below explains the calculation, input rules and interpretation.
When to use Plumbing Control Valve Authority Calculator
Use Plumbing Control Valve Authority Calculator when you need to evaluate the supplied records under the calculation and evidence rules below. No universal controllability threshold, Cv or cavitation index is supplied.
Prepare measured flows, pressures, temperatures or inventories with consistent units. For catalog tools, use independently verified capacities at the stated operating conditions and supply the explicit design demand.
How to use Plumbing Control Valve Authority Calculator and understand its results
- Prepare measured flows, pressures, temperatures or inventories with consistent units. For catalog tools, use independently verified capacities at the stated operating conditions and supply the explicit design demand.
- Enter observedDesignValveDropsKpa, observedRemainingCircuitDropsKpa using the field table and calculation rules, then run the tool.
- Read observedValveAuthorityFractions. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| observedDesignValveDropsKpa | Observed design valve drops kpa | list of number | Required |
| observedRemainingCircuitDropsKpa | Observed remaining circuit drops kpa | list of number | Required |
Enter aligned nonempty nonnegative valve and remaining-circuit kPa drops with positive total drop in every pair. Return authority fractions, including zero and one at valid endpoints.
authority_i=valveDrop_i/(valveDrop_i+remainingCircuitDrop_i) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| observedValveAuthorityFractions | Observed valve authority fractions | list of number |
{
"input": {
"observedDesignValveDropsKpa": [
10,
20
],
"observedRemainingCircuitDropsKpa": [
30,
20
]
},
"output": {
"observedValveAuthorityFractions": [
0.25,
0.5
]
}
}Limitations and assumptions
No universal controllability threshold, Cv or cavitation index is supplied.
Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Numeric lists are limited to 10,000 entries; string lists to 128 strings of at most 128 characters each. The rules above may impose smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Plumbing Hydronic Zone Valve Cv Calculator: Cv uses US gallons per minute and psi with fluid specific gravity. It differs from SI Kv and dimensionless valve authority. For a complementary task, use Plumbing Valve Cavitation Index Calculator: A valve cavitation index compares inlet pressure above vapor pressure with the valve pressure drop. Pressure order controls the sign.
References
Similar or alternative tools
- Plumbing Hydronic Zone Valve Cv Calculator
Cv uses US gallons per minute and psi with fluid specific gravity. It differs from SI Kv and dimensionless valve authority.
- Plumbing Valve Cavitation Index Calculator
A valve cavitation index compares inlet pressure above vapor pressure with the valve pressure drop. Pressure order controls the sign.