I have found these two very useful chemical/mechanical engineering python libraries that I believe can make process calculation breeze in SmathStudio. These are

1] https://github.com/CalebBell/fluids
http://fluids.readthedocs.io/index.html

2] https://github.com/CalebBell/thermo
http://thermo.readthedocs.io/en/latest/

Th 1st one is of particular importance that can turn Smath into a fluid simulation package

Why should I sign-up to see a list of formulas from books [ Hope they are formulas].
I don't care Python and never sign-up. In 1989, our piping Designers used "MassBal".
On my side of the Engineering team: orifice sizing & valves from Sharp calculator.

Jean the idea behind is not the formulas but the easy they are accessed! I mean look at the CoolProps plugin, similarly it would be nice to have a database of Pipes (including the Schedule, Ids, ODs) as well as fittings (non-returns, globe, elbows...).

You mentioned orifice sizing: http://fluids.readthedocs.io/fluids.fittings.html?highlight=orifice

Point is that user would be able to send "Parameters" in already well-defined library functions

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Point is that user would be able to send "Parameters" in already well-defined library functions

Most if not all of those things were standardized well before the 2012 re-invention.
Piping designers have all that in their bible, as well as contraction/expansion 'K'
for control valve sizing. Metering orifice plate is something else [ISO 5167], the
Smath work sheet is done ... do you want it ? more as well "Colebrook stuff".
Control valve sizing is RemToDo.

Thanks, interesting.

I am a man who enjoys learning by examples ...Jean it would be very helpful if you can refer me some chemical/mechanical engineering *.sm sheets (btw I am currently searching this forum too!)
Offtopic: When I press Thanks button on the posts ...popup appears stating "Error Occurred"

Wrote

I am a man who enjoys learning by examples ...Jean it would be very helpful if you can refer me some chemical/mechanical engineering *.sm sheets (btw I am currently searching this forum too!)
Offtopic: When I press Thanks button on the posts ...popup appears stating "Error Occurred"

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The "Thanks" popup error ? Maybe Radovan can help on that.
This forum does not have a "Repository" of models projects, but : "Samples" [today]
contains about 35 pages of each about 15 projects done ... enjoy your bed time reading.
Mechanical is not my cup of tea ! except if purely Physics.
Chemical is simple if from formulas. Otherwise: difficult from "Solving"
In the mean time, enjoy these 4 appetizers.

Jean

Utilities XY [Draw Truss Labels].sm (21 KiB) downloaded 65 time(s).
Inst_Mach Number Pitot.sm (185 KiB) downloaded 63 time(s).
Matrix PseudoInverse.sm (111 KiB) downloaded 58 time(s).
Solve Given_Find [UN CO2].sm (143 KiB) downloaded 64 time(s).