1. Amapayipi ensimbi okuthuthwa kwamanzi negesi (akhandiwe noma angewona amapayipi), amapayipi ensimbi asakazwayo namanye amapayipi, ububanzi bepayipi kufanele buvezwe nge-diameter ye-DN;

2. Ipayipi lensimbi elingenamthungo, ipayipi lensimbi elishiselwe (umthungo oqondile noma ovunguzayo), ipayipi lethusi, ipayipi lensimbi engagqwali namanye amapayipi, ububanzi bepayipi kufanele ivezwe ngobubanzi obungaphandle.× ukujiya kodonga;

3. Amapayipi kakhonkolo aqinisiwe (noma kakhonkolo), amapayipi obumba, amapayipi e-ceramic amelana ne-asidi, amapayipi amathayela angamasilinda namanye amapayipi, ububanzi bepayipi kufanele buvezwe ngobubanzi obungaphakathi d;

4. Ngamapayipi epulasitiki, ububanzi bepayipi kufanele buvezwe ngokwendlela yezinga lomkhiqizo;

5. Uma umklamo usebenzisa i-DN yobubanzi obujwayelekile ukumela ububanzi bepayipi, kufanele kube nethebula lokuqhathanisa le-DN yobubanzi obuncane kanye nezici zomkhiqizo ezihambisanayo.