Valves and Fittings Pressure Drop - Darby 3K Method - Flowmeters

[Stuuus]

Good evening,

Does anyone have any information on the Darby 3K method for the pressure drop due to valves and fittings pertaining to flowmeters of various types. Been unable to obtain K factors for these with this method.

Any help appreciated.

Best Regards,
Stuart

 

[quark]

This data is readily available with flowmeter manufacturers, specific to your case. Why do you want to calculate it?

 

[Stuuus]

I am making a calculations spreadsheet and want to include a means of estimating if for whatever reason the manufacturers values are not available at the time (vessel wifi is notoriously bad).

Pipeline Services Engineer in the Oil & Gas Sector

 

[Latexman]

So, you are at sea now? Very neat, for us land dwellers.

There are so many flow meters and so many sizes, the 3K Method would require a Herculean effort to characterize the lot. If your vessel has a limited number of types/sizes, it may be doable. Do any of your preferred vendors offer downloadable software? That's the not so recent way of doing it. It may be worth an e-mail.

Good luck,
Latexman

To a ChE, the glass is always full - 1/2 air and 1/2 water.

 

[Stuuus]

Not currently, but just trying to be proactive. It's a mammoth spreadsheet as it is, just trying to cover all eventualities.

Take your point about the number of Flowmeters, that'll explain why I haven't had any success. Will just get the values for the ones we currently use and add them in, atleast it's a start.

Thanks alot.

Pipeline Services Engineer in the Oil & Gas Sector

 

[btrueblood]

https://xkcd.com/1906/

 

[georgeverghese]

Keep a copy of Miller's Flow Measurement Handbook with you when you're at sea, if you find it covers most of the flow devices on these ships.

 

[Stuuus]

On a related note, does anyone know how the Darby 3K method is for gas flow?

Pipeline Services Engineer in the Oil & Gas Sector

 

[quark]

Not sure. Both Hooper and Darby gave examples of liquid flow with their methods. I always use equivalent lengths and Panhandle's equation for gas flow.

 

[Latexman]

Never used it. The 1K method (Crane) has worked for me for 38 years, so . . .

Good luck,
Latexman

To a ChE, the glass is always full - 1/2 air and 1/2 water.

 

[georgeverghese]

All the literature I've read so far on the 3K method does not indicate any limitations in gas phase pressure drop estimates. A year or 2 ago, I updated my fittings loss dp mathcad sheet to include predictions based on the 3K method.