Changing the family for a MEP fitting might cause unexpected results.

[thamizhz]

I have faced that problem in revit mep.. also attached picture image. when load family in project. then change parameter value but family cant change . and also family direction automatically rotated. pls rely

[CoreyDaun]

Can you post the Family file here? And what release of Revit is it in?

[thamizhz]

Pls check d attachment 

[CoreyDaun]

I think the problem may stem from the way the Family was built. If you open one of the OOTB inline Pipe Accessory families and navigate to the "Ref. Level" View, you'll see that the fitting is designed 'side-to-side' with the Pipe Connectors on the right and left. Your Family appears to be designed on a different axis; when viewing it from the Ref. Level View, the Pipe Connectors are oriented to top and bottom. You may have to recreate the family in the proper orientation. I have not designed many Pipe/Duct families so it is my assumption that this may be the cause.