Most applications do not need to explicitly free the TStreamAdapter instance. Instead, it is freed automatically when its reference count drops to 0. 

If you must explicitly destroy a TStreamAdapter instance, use the Free method instead of Destoy. Free checks that the TStreamAdapter reference is not nil before calling Destroy. 

Destroy frees the associated stream object (Stream property) if its StreamOwnership property is True. 

Stream 

StreamOwnership 

System::TObject::Free