Feem ntau, hauv kev txhim kho hydropower, cov kav dej qub yuav raug hloov. Cov tuam txhab kev txhim kho hauv tsev thiab cov lag luam pom zoo kom cov neeg kho kom zoo nkauj siv cov kav dej kub thaum txhim kho PPR kav, txawm tias qhov dej txias ntws. Lawv qhov kev sib cav yog vim hais tias cov kev tsis sib xws ntawm cov kav dej kub yog siab dua li cov kav dej txias, thiab tus nqi tsis txawv ntau, cov kav dej kub yog siv rau kev tsim kho dej.
Txoj kab uas hla ntawm cov yeeb nkab PPR (raws li lub taub sab nraud) tuaj yeem nyob ntawm 20mm txog 160mm. Cov khoom siv tseem ceeb hauv tsev kho kom zoo nkauj yog 20 hli (PPR yog 4 kav dej, uas txawv ntawm cov kav dej galvanized), 25 hli (PPR yog 6 kav, uas txawv ntawm cov kav dej galvanized). Muaj qhov sib txawv hauv cov raj) ob hom, uas 20 hli siv ntau dua. Yog tias kev lag luam tso cai, peb pom zoo kom siv cov kav dej PPR nrog ib txoj kab uas hla ntawm 25 hli, tshwj xeeb tshaj yog rau cov kav dej txias, vim cov tsev neeg niaj hnub no muaj ntau cov khoom siv dej ntau dua, thiab qhov tshwm sim ntawm kev siv dej yog siab heev, yog li ua tau Txo qhov teeb meem ntawm cov dej tsis tshua muaj siab thiab cov dej me me.