This partial calculator applies an entered percentage increment to an entered reference pressure and converts that increment to equivalent water head and an ideal lossless velocity-head equivalent. It does not predict steam-injector operation, capacity, efficiency or suitability for a boiler.
Standard Injector - Entered Pressure-Increment Ledger
Explore an entered pressure increment, selected total pressure and ideal water-head equivalents.
Equation Used
- Reference pressure and percentage increment are entered values.
- Water density is fixed at 1,000 kg/m3.
- Equivalent head is a pressure-head conversion.
- Velocity is an ideal lossless velocity-head equivalent, not a predicted flow velocity.
- Injector physics, boiler code and safety are excluded.
The secondary figure is an abstract pressure ledger and does not depict a validated injector geometry.
Entered pressure-increment ledger
The entered increment is Delta p=p_ref M/100 and the selected total is p_ref+Delta p. For an assumed water density of 1,000 kg/m3, equivalent head is Delta p/(rho g); ideal velocity-head equivalent is sqrt(2 Delta p/rho).
What the calculator determines
Use it to inspect pressure arithmetic and ideal water-head equivalences from entered values. It cannot establish injector pickup, delivery, flow, steam use, thermal behavior or valve opening.
Selected relationships
Delta p=p_ref M/100; p_total=p_ref+Delta p; H=Delta p/(rho g); v_equiv=sqrt(2 Delta p/rho), with rho=1,000 kg/m3 and g=9.80665 m/s2.
Selected-input example
At 14 bar reference pressure and an entered 15% increment, Delta p=2.10 bar, selected total pressure=16.10 bar, equivalent water head is about 21.41 m and ideal lossless velocity-head equivalent is about 20.49 m/s.
Not an injector-performance model
Steam state, feedwater temperature, condensation, nozzle geometry, entrainment, mass flow, losses, discharge coefficient, check-valve differential, operating envelope, boiler code and safety are excluded.
Questions
Is 10-15% a validated injector requirement?
No. The percentage is an entered scenario, not a recommendation.
Is the velocity a predicted jet or delivery velocity?
No. It is only the ideal velocity-head equivalent of the selected pressure increment.
Does the source video validate the injector?
No. Its title identifies a three-gear transmission, not an injector.
Actuator motion note for Standard Injector Mechanism
For standard injector mechanism, a linear actuator can be used when the design needs controlled push-pull motion instead of continuous rotary input. The first check is whether the required stroke, speed, and end positions match the mechanism geometry.
When comparing a cylinder to an electric actuator, convert the discussion into stroke, force, speed, duty cycle, and installed length. Matching one specification is not enough.
The clean way to review it is to sketch the linkage at the start, middle, and end of travel. At each position, check the line of action, required force, available clearance, and whether the actuator rod remains close to axial loading.
- Map actuator stroke to the actual output travel before choosing a model.
- Check for binding, changing leverage, and peak load near the ends of travel.
- Decide whether timed motion is acceptable or position feedback is required.
For a FIRGELLI design review, calculate the load case with the FIRGELLI actuator force calculator and plan the switching or controller arrangement with the linear actuator wiring diagram generator. If an actuator or cylinder is already installed, the linear actuator replacement finder helps keep the comparison tied to real dimensions.
References & Further Reading
- Wikipedia contributors. Injector. Wikipedia
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