Apparatus for manufacturing porous glass preform for optical fiber

摘要

An apparatus for manufacturing a porous glass preform for an optical fiber includes a glass synthesizing burner, a gas source for supplying a glass forming gas to the glass synthesizing burner, and a piping for connecting the gas source to the glass synthesizing burner, in which the piping includes at least one layer made of flexible synthetic resin, wherein a ratio of a moisture permeability coefficient P (g.cm/cm².s.cmHg) of the piping to a thickness L of the piping (cm) (P/L) is less than 1.0x10^-10 g/cm².s.cmHg.