1. Gaadiidka biyaha iyo gaaska tuubooyinka birta (galvanized ama non-galvanized), tuubooyinka birta ah iyo tuubooyinka kale, dhexroorka tuubada waa in lagu muujiyaa dhexroorka magaca DN;

2. Dhuumaha birta ah ee aan cillad lahayn, Dhuumaha birta welded (toosan ama wareeg ah), tuubada copper, tuubooyinka ahama iyo tuubooyinka kale, dhexroor tuubada waa in lagu muujiyaa by dhexroor dibadda× dhumucda derbiga;

3. Tuubooyinka dhoobada ah ee la xoojiyay, tuubooyinka dhoobada ah, tuubooyinka dhoobada dhoobada ah, tuubooyinka dhoobada dhoobada iyo tuubooyinka kale, dhexroorka tuubada waa in lagu muujiyaa dhexroorka gudaha d;

4. Tuubooyinka caagga ah, dhexroorka tuubada waa in lagu muujiyaa habka heerka badeecada;

5. Marka nashqadaynta ay isticmaasho dhexroorka magaca ah ee DN si ay u matasho dhexroorka tuubada, waa in uu jiraa miis isbarbardhigga dhexroorka magaca DN iyo sifooyinka alaabta u dhigma.