DN (Bophara ba Lebitso) e bolela bophara bo tloaelehileng ba phaephe, e leng karolelano ea bophara ba kantle le bophara ba kahare. Boleng ba DN = boleng ba De -0.5*boleng ba botenya ba lebota la phaephe. ​​Hlokomela: Hona ha se bophara ba kantle kapa bophara ba kahare.

Phaephe ea tšepe ea phetiso ea metsi, khase (phaephe ea tšepe e nang le galvanized kapa phaephe ea tšepe e seng ea galvanized), phaephe ea tšepe e entsoeng ka tšepe, phaephe ea tšepe-plastiki e kopantsoeng le phaephe ea polyvinyl chloride (PVC), jj., li lokela ho tšoauoa ka bophara bo tloaelehileng ba "DN" (joalo ka DN15, DN50).

De (Bophara ba Kantle) e bolela bophara ba kantle ba phaephe, PPR, phaephe ya PE, bophara ba kantle ba phaephe ya polypropylene, ka kakaretso e tshwailwe ka De, mme tsohle di hloka ho tshwailwe ka sebopeho sa bophara ba kantle * botenya ba lebota, mohlala De25 × 3.

Ka kakaretso D e bolela bophara bo ka hare ba phaephe.

d ka kakaretso e bolela bophara ba kahare ba phaephe ya konkreite. Diphaephe tsa konkreite tse matlafaditsweng (kapa tsa konkreite), diphaephe tsa letsopa, diphaephe tsa ceramic tse hanelang asiti, dithaele tsa silindara le diphaephe tse ding, tseo bophara ba tsona ba phaephe bo lokelang ho emelwa ke bophara ba kahare ba d (jwalo ka d230, d380, jj.)

Φ e emela bophara ba selikalikoe se tloaelehileng; e ka boela ea emela bophara ba kantle ba phaephe, empa lekhetlong lena e lokela ho atisoa ka botenya ba lebota.