Hexavalent chromium (Cr(VI)) nyob rau saum npoo ntawm stainless hlau xovxwm fittings thiab yeeb nkab fittings yog tsim thaum lub sij hawm tej yam kev tsim thiab kev kho mob txheej txheem. Tshwj xeeb, Cr(VI) yuav raug tsim tawm thaum cov txheej txheem hauv qab no:
Kev kho cua sov thiab vuam: Nyob rau hauv qhov kub thiab txias, qhov saum npoo ntawm stainless hlau yuav oxidize, tsim ib oxide txheej uas muaj Cr(VI).
Pickling thiab passivation: Cov txheej txheem kho tshuaj no tuaj yeem tso qee qhov hexavalent chromium residue tom qab kho yog tias cov tshuaj siv muaj chromium.
Plating thiab kho qhov chaw: Hauv qee qhov txheej txheem plating thiab kev kho deg, hexavalent chromium yuav raug tsim yog siv cov tshuaj muaj chromium.
Txhawm rau zam qhov tsim ntawm Cr (VI) ntawm stainless hlau xovxwm fittings thiab cov yeeb nkab fittings, cov kev ntsuas hauv qab no tuaj yeem ua tau:
Kev xaiv cov khoom tsim nyog thiab cov txheej txheem:
Tsis txhob siv cov tshuaj uas muaj chromium.
Xaiv rau lwm qhov tsis muaj chromium thaum twg los tau.
Tswj kev ua haujlwm kub:
Thaum tshav kub kub kho thiab vuam, nruj me ntsis tswj qhov kub thiab txias kom txo tau qhov kub ntawm oxidation uas tuaj yeem tsim Cr(VI).
Optimize Pickling thiab Passivation txheej txheem:
Xaiv cov chromium-free pickling thiab passivation daws.
Xyuas kom huv huv ntawm qhov chaw kom tsis txhob muaj cov tshuaj seem uas tuaj yeem ua rau tsim cov Cr(VI).
Siv cov txheej txheem tiv thaiv:
Siv cov txheej txheem tiv thaiv rau cov hlau tsis huv los tiv thaiv kev tsim ntawm hexavalent chromium thaum kub kub thiab kev kho tshuaj.
European Regulations rau Hexavalent Chromium
Cov kev cai European rau hexavalent chromium nyob rau hauv stainless hlau xovxwm fittings thiab yeeb nkab fittings yog feem ntau xav nyob rau hauv lubRoHS Cov Lus Qhia (Txheej Txheem Cov Tshuaj Tiv Thaiv Kab Mob). Cov lus qhia no txwv tsis pub siv qee yam khoom phom sij, suav nrog hexavalent chromium, hauv cov khoom siv hluav taws xob thiab hluav taws xob. Raws li RoHS Cov Lus Qhia, qhov txwv rau hexavalent chromium yog {{0}}.1% (ie, 1000 ppm). Qhov no txhais tau hais tias tus nqi ntawm hexavalent chromium nyob rau hauv cov ntaub ntawv ntawm cov khoom siv hluav taws xob thiab hluav taws xob tsis tuaj yeem tshaj 0.1% ntawm tag nrho qhov hnyav.
Ntxiv rau, covKev cai REACH (Kev Sau Npe, Kev Ntsuam Xyuas, Kev Tso Cai thiab Kev Txwv Cov Tshuaj)kuj tseem tsim cov kev cai nruj rau kev siv hexavalent chromium. Txoj cai no yuav tsum muaj kev sau npe, kev tshuaj xyuas, kev tso cai, thiab txwv tsis pub cov tshuaj muaj hexavalent chromium kom txo tau lawv qhov cuam tshuam rau ib puag ncig thiab tib neeg kev noj qab haus huv.
Cov ntsiab lus
Txhawm rau kom muaj kev nyab xeeb thiab kev tiv thaiv ib puag ncig ntawm stainless hlau xovxwm fittings thiab yeeb nkab fittings, nws yog ib qho tseem ceeb kom tsis txhob muaj hexavalent chromium thiab ua raws li cov kev cai ntawm European qauv. Los ntawm kev xaiv cov ntaub ntawv tsim nyog thiab cov txheej txheem, tswj kev ua haujlwm kub, ua kom zoo rau kev kho tshuaj, thiab siv cov txheej txheem tiv thaiv, cov tuam ntxhab tuaj yeem txo qhov kev pheej hmoo ntawm Cr(VI) tsim.