Size a steam trap for a drip leg, process heater or known load, estimate the steam, fuel and cost lost by a trap that fails open, and see the payback of repairing the traps in your survey.
USD 39 one-time purchase
Download the sample report (PDF)
Need it once? Use it online: check your data free, unlock results from USD 9 for 3 runs.

What it does
Condensate load three ways
A steam line drip leg, a process heater or exchanger from its duty, or a load you already know.
Required trap capacity
With a safety factor by trap type or your own, plus capacity and pressure classes as screening aids.
Back pressure and flash
Differential pressure, back-pressure ratio and flash steam fraction at the trap discharge, with a warning when back pressure is high.
Cost of a trap failed open
Steam loss from the seat orifice by the isentropic or Napier method, cross-checked, with the annual steam, fuel and cost.
Survey table for 20 traps
Failure rate, total loss, cost of the repair programme, annual saving and payback.
What-if tables
Repair the worst traps first, and a worn seat orifice at larger sizes, with ranked findings and three charts.
Built for engineers
- Visible formulas — nothing hidden, so you can check every step.
- Fully referenced — methods from the standard references, checked against their published worked examples.
- Safe to share — sheets are protected against accidental edits, with an open password so you can still customise.
- Built-in input checks — clear warnings for impossible inputs and values outside typical ranges.
For engineering estimates; verify against site data. Code-based methods are aligned with the publicly documented procedure; they are not a licensed reproduction or a certification.
Preview the workbook
Real pages from the workbook with its built-in example loaded (example data, not a measured plant). Choose a page below, or select the large image to enlarge it.
Specification and checks
| Format | Excel workbook (.xlsx), no macros |
| Version | v1.0 |
| Works in | Excel 2010 or later, Windows and Mac |
| Units | SI, US and British, mixed freely |
| Includes | Guide tab with method and references, calculator, print-ready report |
| Checked against | 149 cases against an independent IAPWS-IF97 Python model: every combination of trap type, load basis, loss method and cost basis, random inputs, US and British units and 54 edge cases; more than 6,900 values agree to better than 1E-9. |
| Free version | Try the free steam pipe sizing calculator |
Online tool or Excel workbook?
| Online tool | Excel workbook (this page) | |
|---|---|---|
| What it does | The same sheet as the Excel workbook, run in your browser | Size a steam trap for a drip leg, process heater or known load, estimate the steam, fuel and cost lost by a trap that fails open, and see the payback of repairing the traps in your survey. |
| Cost | Check your inputs free. Results: 3 runs for USD 9, or every online tool for USD 15 a month (USD 99 a year) | USD 39 once, yours to keep |
| Input checks and findings | Every input checked; findings with the unlocked results | Every input checked, with findings and recommendations |
| Report for your calculation file | Printable results sheet | Print-ready report with your plant, tag, document number, revision and sign-off |
| Formulas | Method described in the guide | Every formula visible in its cell |
| Save, edit and rerun your cases | Each run separately | Yes: keep and edit your own file |
| Works offline, on a plant PC | No, needs the internet | Yes: Excel 2010 or later, Windows and Mac |
Online access and the Excel workbook are separate licences: one does not include the other.
Compatibility, licence and support
| File | Excel workbook (.xlsx), no macros, version v1.0; works in Excel 2010 or later on Windows and Mac. Sheets are protected against accidental edits, with an open password so you can customise. |
| Licence | Single user. A team licence (up to 5 named users) is 3 × the shop price; site licences on request — licence terms. |
| Updates | Updates to this major version are included; download them again from the link in your receipt. |
| Support | Email [email protected] with your order number — questions on the method, your inputs or your results are welcome. |
| Refunds | If the tool does not work as described, or has an error we cannot fix, email [email protected] with your order number within 14 days of purchase and we will refund you in full. Refunds are not offered for a change of mind once a file has been downloaded. Read the full refund policy. |