Plumbing Expansion Tank Size Calculator
Ideal isothermal gas-acceptance expansion tank budget from independently measured expanded volume and explicit absolute pressures; bladder/dead-space/dynamic/code constraints excluded, not pressure vessel approval.
Description
Ideal expansion-tank acceptance follows isothermal gas compression using absolute pressures.
Ideal expansion-tank acceptance follows isothermal gas compression using absolute pressures. Greater maximum pressure provides a positive acceptance fraction.1
The returned values include Ideal isothermal tank acceptance fraction, Required ideal nominal expansion tank liters. The How section below explains the calculation, input rules and interpretation.
When to use Plumbing Expansion Tank Size Calculator
Use Plumbing Expansion Tank Size Calculator when you need to evaluate the supplied records under the calculation and evidence rules below. Bladder, dead-space, dynamic and code constraints are excluded; no pressure-vessel approval 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 Expansion Tank Size 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 callerMeasuredSystemExpansionLiters, callerTankAbsoluteInitialGasPressureKpa, callerTankAbsoluteMaximumGasPressureKpa using the field table and calculation rules, then run the tool.
- Read idealIsothermalTankAcceptanceFraction, requiredIdealNominalExpansionTankLiters. 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 |
|---|---|---|---|
| callerMeasuredSystemExpansionLiters | Caller measured system expansion liters | number | Required |
| callerTankAbsoluteInitialGasPressureKpa | Caller tank absolute initial gas pressure kpa | number | Required |
| callerTankAbsoluteMaximumGasPressureKpa | Caller tank absolute maximum gas pressure kpa | number | Required |
Enter nonnegative measured expansion volume and positive absolute initial/maximum pressures with maximum strictly greater. Return ideal acceptance fraction and nominal tank liters.
acceptance=1−initialAbsolute/maxAbsolute; nominalLiters=expansionLiters/acceptance Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| idealIsothermalTankAcceptanceFraction | Ideal isothermal tank acceptance fraction | number |
| requiredIdealNominalExpansionTankLiters | Required ideal nominal expansion tank liters | number |
{
"input": {
"callerMeasuredSystemExpansionLiters": 2,
"callerTankAbsoluteInitialGasPressureKpa": 100,
"callerTankAbsoluteMaximumGasPressureKpa": 200
},
"output": {
"idealIsothermalTankAcceptanceFraction": 0.5,
"requiredIdealNominalExpansionTankLiters": 4
}
}Limitations and assumptions
Bladder, dead-space, dynamic and code constraints are excluded; no pressure-vessel approval is supplied.
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.
Alternative or Complementary methods
Use Plumbing Hydronic Expansion Tank Acceptance Volume Calculator: Density change estimates hydronic thermal expansion at fixed mass. Installed tank acceptance provides a separate measurable volume budget. For a complementary task, use Plumbing Expansion Tank Precharge Pressure Calculator: A tank’s elevation changes its reference cold-fill gauge pressure. Comparing observed precharge retains the signed mismatch.
References
-
Plumbing Expansion Tank Size Calculator — tool.io
Similar or alternative tools
- Plumbing Hydronic Expansion Tank Acceptance Volume Calculator
Density change estimates hydronic thermal expansion at fixed mass. Installed tank acceptance provides a separate measurable volume budget.
- Plumbing Expansion Tank Precharge Pressure Calculator
A tank’s elevation changes its reference cold-fill gauge pressure. Comparing observed precharge retains the signed mismatch.