New at sizing steam lines 1

[acurry]

I am on my first steam involved project. I am to take steam from my header and drop the temp and pressure.

The header is at 117 psi, 353 deg F, 60,000 #/hr. My equipment needs 5 psi, 248 deg F, 4800 #/hr.

The total feed pipe run will be around 50 feet.

The header is superheated and the equipment feed is a saturated mixture.

Everything online wants to know a velocity, which I do not know.

How should I go about picking a pipe diameter?

 

[21121956]

Hello everybody:

acurry:
Since you are a newcomer in the matter of steam, I would suggest to you start visiting this site:

http://www.spiraxsarco.com/resources/steam-engineering-tutorials.asp.

Good luck!

 

[davefitz]

since you have no concern regarding excess pressure loss, I would suggest sizing teh equipment for a speed equal to 15% of soundpseed at the max flow case.

 

[insult2injury]

Being that the steam is not that much above saturation, you may want to consider lower velocities, especially if there are 90 degree elbows.

I2I

 

[timbones]

What a great resource that spiraxsarco website is! thanks for the link.

I have a few guides for selecting pipe sizes. One guide uses a pipe velocity of 100 ft/s for saturated steam pipes larger than 8" and pressures under 25 psig. The same guide recommends a velocity of 160 ft/s for saturated steam over 25 psig and pipe sizes over 8". For smaller sizes, it recommends lower velocities.

Of course this is just a guide for selecting economic pipe sizes. Everyone has slightly different ideas on what are good velocities to use. You should also still check pressure losses and such.