Plumbing Ejector Pump Capacity Calculator
Audit actual sewage ejector measured pump/inflow/cycle inventory and caller maximum starts, distinct from inverse sump duty sizing; no solids handling, ventilation or wastewater safety assurance.
Description
A sewage ejector cycle alternates filling and net draining.
A sewage ejector cycle alternates filling and net draining. Cycle frequency depends on measured inflow, pump rate and usable wetwell volume.1
The returned values include Modeled ejector on minutes, Modeled ejector off minutes, Modeled starts per hour, Within caller starts policy. The How section below explains the calculation, input rules and interpretation.
When to use Plumbing Ejector Pump Capacity Calculator
Use Plumbing Ejector Pump Capacity Calculator when you need to evaluate the supplied records under the calculation and evidence rules below. No solids handling, ventilation or wastewater safety assurance 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 Ejector Pump Capacity 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 observedEjectorPumpLitersMinute, observedConcurrentSewageInflowLitersMinute, observedUsableWetwellCycleLiters, callerMaximumStartsPerHour using the field table and calculation rules, then run the tool.
- Read modeledEjectorOnMinutes, modeledEjectorOffMinutes, modeledStartsPerHour, withinCallerStartsPolicy. 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 |
|---|---|---|---|
| observedEjectorPumpLitersMinute | Observed ejector pump liters minute | number | Required |
| observedConcurrentSewageInflowLitersMinute | Observed concurrent sewage inflow liters minute | number | Required |
| observedUsableWetwellCycleLiters | Observed usable wetwell cycle liters | number | Required |
| callerMaximumStartsPerHour | Caller maximum starts per hour | number | Required |
Enter positive pump flow, inflow, cycle liters and maximum starts/h, with pump flow strictly above inflow. Return on/off minutes, starts/h and an inclusive maximum-starts flag.
onMinutes=volume/(pump−inflow); offMinutes=volume/inflow; startsPerHour=60/(on+off) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| modeledEjectorOnMinutes | Modeled ejector on minutes | number |
| modeledEjectorOffMinutes | Modeled ejector off minutes | number |
| modeledStartsPerHour | Modeled starts per hour | number |
| withinCallerStartsPolicy | Within caller starts policy | boolean |
{
"input": {
"observedEjectorPumpLitersMinute": 30,
"observedConcurrentSewageInflowLitersMinute": 10,
"observedUsableWetwellCycleLiters": 40,
"callerMaximumStartsPerHour": 12
},
"output": {
"modeledEjectorOnMinutes": 2,
"modeledEjectorOffMinutes": 4,
"modeledStartsPerHour": 10,
"withinCallerStartsPolicy": true
}
}Limitations and assumptions
No solids handling, ventilation or wastewater safety assurance 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. A successfully returned false flag is an evaluated outcome; its meaning is explained above.
Alternative or Complementary methods
Use Plumbing Sump Pump Capacity Calculator: A sump cycle alternates filling while the pump is off and net draining while it is on. A chosen on-time fraction determines pump capacity for steady inflow. For a complementary task, use Plumbing Detention Basin Volume Calculator: Detention storage routes chronological inflow and requested outflow from an empty basin. Clipping storage at zero reveals unavailable outlet demand.
References
Similar or alternative tools
- Plumbing Sump Pump Capacity Calculator
A sump cycle alternates filling while the pump is off and net draining while it is on. A chosen on-time fraction determines pump capacity for steady inflow.
- Plumbing Detention Basin Volume Calculator
Detention storage routes chronological inflow and requested outflow from an empty basin. Clipping storage at zero reveals unavailable outlet demand.