There are many problems. Please help.

[whrudwls111]

 Hello. 

I am a student studying revit in Korea. 
Please understand that sentences can be strange using translators.

The first problem is
I created two families and loaded and combined them into one file. 
Loading to the project results in a line. After viewing the combined file, I deleted the connector of the loaded file and the line disappears. Can't we get the lines to disappear without deleting the connector?

Question two :
When mep is modeled and edited in some valves and pipes, the shape is rectangular
Does Insulation not shape? 

There is not much information in Korea so it is hard to find it. Please help me.

[RakMas]

you need to attach the project file and the created families in order for anyone here to help you, your explanation is very vague

[Anonymous]

Adding said revit families may give us an idea what you are looking at. 

From what you have said so far:

Revit Family - the connector is associated with the surface you selected. Even when deleting that connector, the associated part stays. I would make sure your level of detail is set. Depending on you built those families, the family will appear differently between Coarse, Medium and Fine. the view you are loading that family in, make sure you have it set accordingly.  If you set it to Fine, does it appear as it should?

Pipe insulation does take shape.