Modeling a PRV in a steady state analysis

[tylerz28ss]

Hey guys, I'm new to the forum and am in need of some tips here. I am using WaterCAD to model a new water distribution system for a subdivision. The initial results of my model tell me that I need some Pressure Reducing Valves...the only problem is that the PRV's close instantaneously due to the pressures exceeding my controls; thus disconnecting the rest of my system.

Are there any other ways to model PRV's in steady state analysis...Thanks!

 

[BigInch]

Will EPAnet allow you set the percent open?

BigInch-born in the trenches.

http://virtualpipeline.spaces.msn.com

 

[tylerz28ss]

Well, I've never used EPAnet...

 

[BigInch]

Sorry.. WaterCAD. I've never used either of them. I can force a valve to move to a particular % open, thus changing the Cv.

BigInch-born in the trenches.

http://virtualpipeline.spaces.msn.com

 

[tylerz28ss]

I just checked and unfortunately, the valves are modeled as either off or on...

 

[BigInch]

Bad news.

Can you change the Cv or Valve size? Maybe you can use a full open 4" valve to simulate a 12" at 25% open or something.

BigInch-born in the trenches.

http://virtualpipeline.spaces.msn.com

 

[sjohns4]

Can you give a breif description of the system? I'll give it a shot w/ Water CAD.

 

[hydrae]

Tylerz28ss
I would check the controls on the prv, It should self modulate to give the desired results. if it is closing, is it backwords? do you have demands on both sides of the valve? is your source stable?
Hydrae