Engineering Calculators
Engineering calculator workbench.
Choose a utility from the compact index and work with the calculator on this page.
Need analyzer-specific help after an engineering check?
Use these calculators as front-end utilities, then bring process conditions, gas composition, and design constraints to GESHINE for analyzer selection and RFQ support.
Pressure Drop & Inside Film Coefficient Calculator
This calculator allows the user to input the average fluid temperature, pressure, percent vapor, flow rate, pipe size, number of passes, and the necessary fluid properties. The calculator then determines the velocity, the Reynolds number, the Fanning friction factor, the pipe friction factor,the pipe velocity head and the pipe friction loss in psi.
These correlations may be used for compressible fluids or mixtures, but should be used with caution since average conditions, not actual inlet and outlet properties are being used. In general, if the pressure drop is greater than 40% of the inlet conditions, these equations should not be used. If wall film temperature and viscosity are not known, input bulk properties.
Ducting Pressure Drop Calculator
The following formulas and coefficients are from the American Petroleum Institute Practice API RP533.
Gas Side Pressure Drop Across Bare Tubes
The gas side pressure drop may be calculated by any number of methods available today, but the following procedures should give sufficient results for heater design.
Gas Side Pressure Drop Across Finned Tubes
The gas side pressure drop may be calculated by any number of methods available today, but the following procedures should give sufficient results for HRSG design. Refer to the previous pages for source of the correlations.
Gas Side Pressure Drop Across Studded Tubes
The gas side pressure drop may be calculated by any number of methods available today, but the following procedures should give sufficient results for heater design. Refer to previous pages for source and explanation of these procedures.
Return Bend Equivalent Length Calculator
Equivalent Length Of Return Bends & Elbows: Method used in WinHeat Software
The equivalent length of a return bend may be obtained from the following curves based on Maxwell table and corrected using the Reynolds number correction factor.
| FactNre = Reynolds number correction |
| Lrb = Equivalent length of return bend, ft |
 |
 |
Where,
| G = Mass velocity, lb/sec-ft2 |
| Di = Inside tube diameter, in |
| Visc = Viscosity, cp |
| Description | Velocity Heads | Equivalent Length, Tube Dia |
| Long Radius 90° Elbow | 0.30 | 16.5 |
| Short Radius 90° Elbow | 0.50 | 27.5 |
| Long Radius 180° Return | 0.50 | 27.5 |
| Short Radius 180° Return | 0.75 | 41.25 |
| Velocity Head | 1.00 | 55 |
Calulations based on above data:
Friction Loss:
| Dp = Pressure drop, psi |
| di = Inside diameter of tube, in |
| G = Mass velocity of fluid, lb/sec-ft2 |
| Vlm = Log mean specific volume correction |
| F = Fanning friction factor |
| Lequiv = Equivalent length of pipe run, ft |
| V1 = Specific volume at start of run, ft3/lb |
| V2 = Specific volume at end of run, ft3/lb |
Fluegas Acid Dewpoint Calculator
Flue Gas Properties Calculator
Supplemental Firing Calculator
- Gas or Liquid Fuel Combustion based on Excess Air or O2 in Stack
- Fired Furnace Efficiency with Air Preheat using External Heat Source
- Fired Furnace with Integrated Air Preheat System Analysis
- Existing Fired Furnace with added Air Preheat System Analysis
- And many other configurations...
Disclaimer:
The formulas and correlations presented herein are all in the public domain and are to be used only as a learning tool. Note that any product, process, or technology in this document may be the subject of other intellectual property rights reserved by sponsors or contributors to this site. This publication is provided as is, without any warranty of any kind, either expressed or implied, including, but not limited to, the implied warranties of fitness for a particular purpose, or non-infringement.
The formulas, correlations, and methods presented herein should not be considered as being recommended by or used by the sponsors of this site. The purpose of this site is educational and the methods may or may not be suitable for actual design of equipment. Only a fired heater design engineer is qualified to decide if a calculation or procedure is correct for an application.
Convection Overall Heat Transfer Coefficient Calculator
Insulation and Heat Loss Calculator
Metals Thermal Conductivity Calculator
Steam Properties Calculator
Steam Drum Volume Calculator
This calculator calculates the various water storage volumes and time between the levels for typical steam drums. The JacaScript assumes 2:1 eliptical heads on the drum.
API 530 Tube Wall Thickness Calculator
This calculator uses curve fits of the stress values and formulas from the API RP 530 to calculate the minimum tube wall required.