1. Cov dej tsis kam ntawm PPR yeeb nkab khoom yog qhia los ntawm softening Vicat coefficient. Lub softening Vicat coefficient ntawm dej-cov ntaub ntawv resistant muaj qhov zoo ntawm cov cua sov, siab -kub dej kub, qhib nteg installation thiab dej rau sab nraum zoov thiab cov kav dej thov. Lub softening coefficient qhia txog qib ntawm lub zog txo ntawm cov khoom tom qab immersion nyob rau hauv dej, uas feem ntau fluctuates ntawm 0-1. Qhov me me ntawm softening coefficient, qhov qis zog ntawm cov khoom tom qab nqus dej thiab saturation, yog li nws cov dej tsis kam. Rau cov ntaub ntawv ntawm cov qauv tseem ceeb feem ntau nyob hauv dej los yog cuam tshuam loj heev los ntawm cov dej noo, qhov softening coefficient yuav tsum tsis txhob tsawg dua. Lub softening coefficient ntawm cov ntaub ntawv nrog lub teeb noo noo los yog lwm yam qauv yuav tsum tsis txhob tsawg tshaj li 0.75. Cov ntaub ntawv nrog softening coefficient ntau dua 0.80 feem ntau tuaj yeem suav tias yog cov khoom siv dej-resistant.
2. Qhov tshwm sim ntawm thermal expansion thiab txias contraction ntawm cov kav dej kuj yog inevitable. PPR pipeline xaiv los ntawm dej- cov ntaub ntawv tiv taus tau txhim kho kev nruj thiab tsis yooj yim rau sag thaum tso cov kav dej kab rov tav, uas ua rau kom muaj kev zoo nkauj ntawm cov kav dej, txhim kho qhov khoov ntawm cov kav dej, thiab tseem nyob ruaj khov ntawm qhov siab. kub.
3. Kev sib txuas thiab tiv thaiv kev ua haujlwm ntawm cov dej-cov yeeb nkab tiv thaiv yuav tsum tau them nyiaj rau. Raws li kev soj ntsuam ntawm cov yam ntxwv ntawm cov yeeb nkab, PPR yeeb nkab hom kab ntau lawm tau tsim thiab tsim ib qho tshwj xeeb txhuas stripping cuab yeej los tev tawm ntawm txhuas txheej thiab txheej txheej ntawm PPR, uas tuaj yeem txuas nrog kub {{2} }melt qhov (socket) txoj kev, uas tshem tawm qhov ua rau kom yooj yim rau hauv kev sib txuas ntawm cov yeeb nkab PPR zoo tib yam nrog cov yeeb nkab tooj liab, thiab zoo dua yog cov yeeb nkab kom paub txog nws cov dej tsis kam.
