Plumbing Pump Affinity Head Calculator
Calculate actual measured pump head affinity scenario at caller speed under independently verified same-impeller/fluid similarity; exponent 2, not a pump curve intersection, efficiency guarantee or operating instruction.
Description
Pump affinity head scales with speed squared under fixed impeller and fluid similarity.
Pump affinity head scales with speed squared under fixed impeller and fluid similarity. It estimates a corresponding ideal point.1
The returned values include Ideal query head m, Ideal speed ratio. The How section below explains the calculation, input rules and interpretation.
When to use Plumbing Pump Affinity Head Calculator
Use Plumbing Pump Affinity Head Calculator when you need to evaluate the supplied records under the calculation and evidence rules below. No actual operating-point or safe-speed determination 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 Pump Affinity Head 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 observedReferenceHeadM, observedReferenceSpeedRpm, callerQuerySpeedRpm, callerSameImpellerAndFluidVerified using the field table and calculation rules, then run the tool.
- Read idealQueryHeadM, idealSpeedRatio. 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 |
|---|---|---|---|
| observedReferenceHeadM | Observed reference head m | number | Required |
| observedReferenceSpeedRpm | Observed reference speed rpm | number | Required |
| callerQuerySpeedRpm | Caller query speed rpm | number | Required |
| callerSameImpellerAndFluidVerified | Caller same impeller and fluid verified | boolean | Required |
Enter nonnegative reference head, positive reference and query speeds, and a true independently verified same-impeller/fluid flag. A false flag is an input error. Return ideal head and speed ratio.
ratio=queryRpm/referenceRpm; queryHead=referenceHead×ratio² Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| idealQueryHeadM | Ideal query head m | number |
| idealSpeedRatio | Ideal speed ratio | number |
{
"input": {
"observedReferenceHeadM": 10,
"observedReferenceSpeedRpm": 1000,
"callerQuerySpeedRpm": 1500,
"callerSameImpellerAndFluidVerified": true
},
"output": {
"idealQueryHeadM": 22.5,
"idealSpeedRatio": 1.5
}
}Limitations and assumptions
No actual operating-point or safe-speed determination 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 Pump Affinity Power Calculator: Pump affinity power scales with the cube of speed under fixed impeller and fluid similarity. Actual system operation can depart from that ideal. For a complementary task, use Plumbing Pump Affinity Flow Calculator: Pump affinity flow scales directly with speed under fixed impeller and fluid similarity. The system curve can alter the operating flow.
References
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Plumbing Pump Affinity Head Calculator — tool.io
Similar or alternative tools
- Plumbing Pump Affinity Power Calculator
Pump affinity power scales with the cube of speed under fixed impeller and fluid similarity. Actual system operation can depart from that ideal.
- Plumbing Pump Affinity Flow Calculator
Pump affinity flow scales directly with speed under fixed impeller and fluid similarity. The system curve can alter the operating flow.