[SteveM]

Hi Guys,

I am new here, great to see a community for things like this.

I have found this place through coming up against an issue I seem unable to solve.

I have a pipe line assembly that we have physically tested, we introduced the flow to the pipe and monitored this along with the pressure drops, temps etc.

The real results showed that at 295.57 US Gal / min there was a pressure drop of 1 PSI naturally occurring, so after calculation would result in a CV value of 295.57 aswell.

Now, I have taken all the data, worked up an average and also ran individual tests to work out the compensation for losses in the test equipment and get an average CV value of 304. So not too far away.

I have simulated this in floefd as an external flow with the inlet capped and set at X US Gal/min, the pipeline follows with the same pressure point indicators as the test equipment, with an extended tube after that running out to atmosphere. (This was the only way I was aware of how to input just the x US Gal/min and get a result) anyway, these results came out to within 1% of the real tests, so at that point I am quite comfortable that the CV would be 295.57 or there abouts.

HOWEVER,

When I am running a CV check on other assemblies which I have not tested, my normal set up is to have inlet and outlet tubes running from my assemblies and then have the inlet as 2 PSI and the outlet as 1 PSI controlling the pressure drop, using water and monitoring the flow at the 1 PSI point, this in my opinion eliminates the variables from the CV equation and means the flow would be the CV, much like my real tests. However this results in a flow of 210 US Gal/min.

Sorry if I missed any information which would be crucial to solving this but if you have any questions I would be happy to reply with further information, I imagine I am overlooking something relatively simple, but this has lost my faith in the software at the moment.

Cheers,

SteveM