1. Ruwa da iskar gas sufuri na karfe bututu (galvanized ko wadanda ba galvanized), jefa baƙin ƙarfe bututu da sauran bututu, da bututu diamita ya kamata a bayyana da maras muhimmanci diamita DN;

2. Bututun ƙarfe mara nauyi, welded karfe bututu (daidai ko karkace kabu), jan karfe bututu, bakin karfe bututu da sauran bututu, da bututu diamita ya kamata a bayyana da m diamita.× kauri bango;

3. Ƙarfafawar siminti (ko kankare) bututu, bututun yumbu, bututun yumbu mai jure acid, bututun tile na silinda da sauran bututu, diamita bututu ya kamata a bayyana ta diamita na ciki d;

4. Don bututun filastik, ya kamata a bayyana diamita na bututu bisa ga hanyar samfurin samfurin;

5. Lokacin da zane ya yi amfani da diamita na DN don wakiltar diamita na bututu, ya kamata a sami tebur kwatanta na diamita na DN da kuma samfurin samfurin daidai.