Which steam properties and standards does LOGOS Steam use?

Every calculator uses the same IAPWS-IF97 engine for saturated, superheated and wet steam, with viscosity and thermal conductivity from IAPWS R12-08 and R15-11. Control valves follow IEC 60534-2-1, safety valves follow API 520 Part I and API 526, line heat loss follows ISO 12241 and condensate lines follow FCI ST-108. The engine is cross-checked against iapws, CoolProp and fluids and against published examples such as API 520 Example 4.

Why calculate a start-up scenario for steam lines and traps?

At start-up the control valve is wide open, the consumer is cold and the flow can be blocked, so velocity, Mach and condensate load are far from the design point. LOGOS Steam calculates the start-up flow alongside maximum and minimum operation, and checks the steam trap at start-up, minimum pressure, minimum load and stall.

Does LOGOS Steam generate a calculation report?

Yes. All 10 steam calculators generate a Word (.docx) report with the inputs, formulas, cited references and a verdict per item: meets, meets with open items or does not meet. They run on the server, so an account is required.

LOGOS Steam · IAPWS-IF97 · IEC 60534-2-1 · API 520 / 526

Steam systems sized for maximum, minimum and start-up — not only for the design point.

Size steam lines, ring and radial networks, condensate return and steam traps, pressure-reducing stations, desuperheaters, control valves and safety valves and the consumers that load the network — heat exchangers, jacketed vessels and steam-water mixers — on one IAPWS-IF97 engine, with a calculation report in Word for every one of them.

Create free account See the calculators ↓

10: steam calculators
IF97: IAPWS-IF97 engine for all of them
3: operating scenarios: maximum, minimum, start-up
.docx: report ready to sign

Your steam system lives in spreadsheets fed by a printed steam table, each consumer in its own file and none of them knows what happens at start-up. Which number goes into the project?

Printed tables, typed properties

Enthalpy, specific volume and saturation temperature copied from a table and interpolated by hand. Change the pressure and every cell downstream depends on someone remembering to update it.

Lines checked only at full load

A line sized for the design flow says nothing about the start-up: valve wide open, cold consumer, blocked flow. That is where velocity and Mach run away — and the start-up flow should be calculated, not guessed.

Traps sized by load, consumers in isolation

A steam trap "sized" only by condensate load ignores start-up, minimum pressure, back pressure and stall. A consumer calculated outside the network ignores the pressure it actually receives.

From the steam balance to the report, in three steps.

01
Enter the system in bar(g), °C and kg/h

Header pressure and temperature, line routes with fittings and elevation, insulation, consumers and their duty — the data you already have in the steam balance and the piping layout.
02
Calculate the three scenarios

Maximum, minimum and start-up, with the start-up flow calculated from the valve wide open and the cold consumer. All properties come from the same IAPWS-IF97 engine — saturated, superheated or wet steam.
03
Download the report in Word

A calculation report with the inputs, formulas, cited references and a three-level verdict per item: meets, meets with open items, does not meet. What has no documented basis is reported as not evaluated.

What you size here.

All 10 steam calculators, on one IAPWS-IF97 engine — every one runs on the server, so an account is required.

Distribution and condensate

Pressure reduction and valves

Steam consumers

The whole steam system on one engine — not a spreadsheet per consumer.

Spreadsheets are flexible but run on typed table values and nobody audits them; vendor sizing tools cover their own products, and process simulators are not built to produce a line-by-line sizing report. LOGOS sizes lines, network, condensate, valves and consumers on the same IAPWS-IF97 engine, on the web.

Feature	LOGOS	Excel spreadsheet	Vendor tool or simulator
Price	Free to start	Free	free for one brand, or a licence
Calculation report in Word	✓	✕	sometimes
Standardized, citable methods	✓	depends on who built it	✓
Traceability and versioning	✓	✕	partial
Nothing to install (web)	✓	✓	✕
Network, consumers and start-up together	✓	✕	one item or one brand at a time
Methods per IAPWS, IEC, API and ISO	IAPWS · IEC · API · ISO	—	vendor rules or own model
Learning curve	minutes	inherited and fragile	one tool per brand, or weeks of training

Informative comparison, based on the typical use of each alternative. “Vendor tool or simulator” refers to the sizing tools steam equipment manufacturers distribute for their own products and to general-purpose process simulators.

Every property and every limit has a reference behind it.

No black box. Properties come from IAPWS-IF97 and the IAPWS transport releases; valves follow IEC 60534-2-1 and API 520 / 526; heat loss follows ISO 12241. The engine is cross-checked against open libraries (iapws, CoolProp, fluids) and published worked examples.

IAPWS-IF97
IAPWS R12-08 · R15-11
IEC 60534-2-1
API 520 Pt I (10ª ed.) · API 526
ISO 12241
FCI ST-108
Darcy-Weisbach · Colebrook-White
Spirax Sarco (referência técnica)

Free while the open beta runs.

Open beta

Every account gets full access — all disciplines, every calculator, no project or seat limit. No credit card, no deadline.

Hydraulics and electrical — all 34 calculators, every one
Projects, Kanban and deadlines
Calculation report in Word (.docx), no watermark
2D and 3D diagrams on every result

Create a free account

Pricing will be published before the beta ends, and nothing is charged unless you subscribe first.

“I am an engineer. I got tired of steam lines checked only at design flow, traps picked from a load figure and consumers calculated as if the network did not exist. I built LOGOS Steam to give every steam calculation what those spreadsheets never had: provenance.”

— the team behind LOGOS