Hana ʻia ʻo Prestressed Post tensioning spiral concrete construction Galvanized Sheet Spiral Ducting Corrugated
ʻO ka mīkini paipu corrugated he ʻano mea hana no ka hana ʻana i ke koʻikoʻi pre-stressed reserved tunnel metala bellows e hana i ka galvanized steel strip coil i ʻehā wave shape then undercuts and swages to apply the bellows, which With high efficiency and small volume, Easy operation and maintenance, convenient a hiki ke hoʻololi i ka wikiwiki.He kūpono ia no ka hoʻohana kikowaena ma nā kahua kūkulu a me nā hale hana.