Lokhu kushiwo ukuhlinzeka ngezinga lokukhiqiza lesistimu yamapayipi ukuhambisa amanzi, igesi kanye nowoyela ezimbonini zikawoyela negesi yemvelo.
Kunamazinga amabili wokucaciswa komkhiqizo, i-PSL 1 ne-PSL 2, i-PSL 2 inezidingo eziyisibopho zokulingana kwekhabhoni, ukuqina kwe-notch, amandla aphezulu wokukhiqiza namandla aqinile.