Steam pipeline pressure drop 1

For clarity - Do you mean a pressure reducing valve?

What is "rating of the steam" ?

MJCronin
Sr. Process Engineer

I'm pretty sure he meant a pressure reducing valve.

Doomster, when pressure is reduced through a valve you may consider it an isenthalpic process. Basically, calculate the enthalpy of your steam upstream of the valve, then find your new steam properties with the same enthalpy and new pressure downstream of the valve.

Daniel
Rio de Janeiro - Brazil

doomster said:

will the mass and rating of the steam changes after it passes through the PRV?

Click to expand...

I will clarify by rewording this to, will the pressure, temperature, and density of the steam change after it passes through the PCV?

Yes, as danschwind has pointed out.

Good Luck,
Latexman

Try this
You do need to know temperature of your steam as well as start pressure - i.e. saturated steam or super heated?

Mass will not change either side of the valve.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

The Sarco website is a good place to start. The Sarco site has the steam tables you need to find the answer. Enthalpy across a valve is constant like danschwind indicates.

Things to consider -
If you reduce the pressure at the front end of a pipeline, the user will see more pressure droop than if you reduce the pressure close to the end user.
You can get the same effect by reducing the boiler pressure setpoint.

Check your pipeline pressure drop, at lower pressures the volume (keeping the mass constant) increases, so velocity increases and the pressure drop increases. If the velocity gets to sonic, the flow will choke.

Fred

Use a steam table and use constant enthalphy. Or use the links provided above