valve sizing .ddb file

A guy in our mechanical group sized some control valves for a project and the contractor is unable to order a valve that meets the Cv values listed in the schedules.

I have found in the project folder what appears to be valve sizing software files for each valve, which might help identify what make/model of valve the schedule is based on. Do any of you recognize a .ddb file extension to help me determine what software might have been used?

http://www.file-extensions.org/ddb-file-extension-device-dependent-bitmap-graphics-file

Just a guess.

-rpoet

Looks like an old Dbase file to me.

It may not be necessary to match the Cv value. A larger Cv value than specifeid means a lower pressure drop (Cv is the gpm of water a valve will pass at 1.0 psi pressure differential.) If the Cv is slightly lower the difference won't be significant.

Have you tried talking to the design engineer to find out the basis for the specified value and to determine how much variance is allowed?

Valve Cvs are never exact, you calculate the required Cv and then pick a valve a bit larger.
Most valve vendors will re-check the Cv calculation again, if you have a datasheet.
Roy