Plumbing Valve Choked Flow Check Calculator
Audit actual liquid valve drop against explicit caller FL and FF=.96−.28√(Pv/Pc) threshold, absolute pressures; excludes gases/two-phase flow, no valve-operating or pressure safety approval.
Description
Liquid choked-flow screening compares observed valve pressure drop with a pressure-recovery threshold.
Liquid choked-flow screening compares observed valve pressure drop with a pressure-recovery threshold. Absolute pressure is required for the vapor-pressure term.1
The returned values include Modeled liquid choked drop threshold kpa, Observed valve drop kpa, Caller liquid choked criterion reached. The How section below explains the calculation, input rules and interpretation.
When to use Plumbing Valve Choked Flow Check Calculator
Use Plumbing Valve Choked Flow Check Calculator when you need to evaluate the supplied records under the calculation and evidence rules below. This liquid model does not certify cavitation protection, gas flow or valve safety.
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 Valve Choked Flow Check 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 observedUpstreamAbsoluteKpa, observedDownstreamAbsoluteKpa, callerVaporAbsoluteKpa, callerCriticalAbsoluteKpa, callerLiquidRecoveryFactor using the field table and calculation rules, then run the tool.
- Read modeledLiquidChokedDropThresholdKpa, observedValveDropKpa, callerLiquidChokedCriterionReached. 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 |
|---|---|---|---|
| observedUpstreamAbsoluteKpa | Observed upstream absolute kpa | number | Required |
| observedDownstreamAbsoluteKpa | Observed downstream absolute kpa | number | Required |
| callerVaporAbsoluteKpa | Caller vapor absolute kpa | number | Required |
| callerCriticalAbsoluteKpa | Caller critical absolute kpa | number | Required |
| callerLiquidRecoveryFactor | Caller liquid recovery factor | number | Required |
Enter positive absolute inlet, outlet and critical pressures, nonnegative vapor pressure, and FL in (0,1]. Require outlet≤inlet, vapor≤critical and positive computed threshold. Return pressure drop, threshold and a flag for drop at least threshold.
FF=.96−.28sqrt(vaporPressure/criticalPressure); threshold=FL²(P1−FF×vaporPressure) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| modeledLiquidChokedDropThresholdKpa | Modeled liquid choked drop threshold kpa | number |
| observedValveDropKpa | Observed valve drop kpa | number |
| callerLiquidChokedCriterionReached | Caller liquid choked criterion reached | boolean |
{
"input": {
"observedUpstreamAbsoluteKpa": 200,
"observedDownstreamAbsoluteKpa": 100,
"callerVaporAbsoluteKpa": 10,
"callerCriticalAbsoluteKpa": 1000,
"callerLiquidRecoveryFactor": 0.8
},
"output": {
"modeledLiquidChokedDropThresholdKpa": 122.03520000000003,
"observedValveDropKpa": 100,
"callerLiquidChokedCriterionReached": false
}
}Limitations and assumptions
This liquid model does not certify cavitation protection, gas flow or valve safety.
Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors. A successfully returned false flag is an evaluated outcome; its meaning is explained above.
Alternative or Complementary methods
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. For a complementary task, 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.
References
Similar or alternative tools
- 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.
- 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.