I used George Fischer (GF) PVC Pipe and Fittings ITMs to create a new Service in CADmep. 

When drawing the pipe in Design Line, the pipe lengths, most fittings (elbows, tees, bushings, etc.) work as expected.  The pipe, though, just connects pipe-to-pipe, no couplings are inserted if the pipe exceeds 20 ft. 

The Pipe C1/C2 =  GF Sch 80 PVC Plain End (Pipe Sched90 PE,itm)   TNFAB v5

The Coupler C1/C2 = GF_HUB-PVC Coupling Sch80 Adsk Data v4,

Connectivity for C1/C2 = None

Changing the Coupling C1/C2 Connectivity = PVC (Pipe Sch80 PE.itm) TNFABv2 - makes no difference.

How do I set up the PVC Coupler as a Connector for the PVC pipe in Design Line?

Thanks,