E mafai ona tatou gaosia ituaiga eseese o palasitika manhole laʻasaga, o loʻo i ai a tatou faʻasologa atoa o laasaga, e pei o le Umea, Carbon steel, stainless steel, alumini ma palasitika encapsulated.
E mafai fo'i ona matou atia'e ni ata fou ma ata a tagata fa'atau po'o fa'ata'ita'iga.
E maua nisi fa'amatalaga pe a maua lau su'esu'ega.
1) DIN19555/EN13101
2) BS1247