DN (Nominal Diameter) e bolela bophara ba lebitso la phaephe, e leng karolelano ea bophara ba ka ntle le bophara bo ka hare. Boleng ba DN = boleng ba De -0.5* boleng ba botenya ba lebota la tube. Tlhokomeliso: Sena ha se bophara ba bokantle kapa bophara bo ka hare.

Metsi, peipi ea tšepe e fetisang khase (peipi ea tšepe e entsoeng ka masenke kapa peipi ea tšepe e sa keneng), peipi e entsoeng ka tšepe, phala ea tšepe ea polasetiki le polyvinyl chloride (PVC) joalo-joalo, li lokela ho tšoauoa bophara ba "DN" (joalo ka DN15). , DN50).

De (Bophara ba ka ntle) e bolela bophara bo ka ntle ba phala, PPR, phala ea PE, phala ea polypropylene bophara ba bokantle, ka kakaretso e tšoauoa ka De, 'me kaofela li hloka ho tšoauoa e le sebopeho sa bophara ba bokantle * botenya ba lebota, mohlala De25 × 3 .

D ka kakaretso e bua ka bophara bo ka hare ba phala.

d ka kakaretso e bua ka bophara bo ka hare ba phala ea konkreite. Liphaephe tsa konkreite tse matlafalitsoeng (kapa konkreite), liphaephe tsa letsopa, liphaephe tsa ceramic tse hananang le asiti, lithaele tsa cylinder le liphaephe tse ling, tseo bophara ba tsona ba phaephe e lokelang ho emeloa ke bophara bo ka hare ba d (joalo ka d230, d380, joalo-joalo)

Φ e emela bophara ba selikalikoe se tloaelehileng; e ka boela ea emela bophara bo ka ntle ba phala, empa lekhetlong lena e lokela ho atolosoa ke botenya ba lerako.